World's Most Dangerous Sharks MEGA EPISODE - Top 5 Full Episodes | Sharkfest

NARRATOR: The coast of Florida has been host to countless tales of behemoth great hammerheads. Sharks rivaling the great white in size, and weighing over 1000 pounds. But in there any truth to these fisherman's tales? MALE: Get out of the water. MALE: Big hammerhead! MALE: Get of out there. DEMIAN: There are several species of hammerheads. And they're sort of the new kids on the block as far as evolution of sharks goes. YANNIS: Great hammerheads are a bit different from some of the other species in that they tend to be more solitary, but they also get much

larger. NARRATOR: The maximum size of great hammerheads has long been disputed by science, but historical accounts and numerous modern-day sightings have put their true potential into question. CAPT ROB: He just took it outta my hand! CANDACE: There's a lot of local lore and fish tales about how large these animals can get. MALE: Oh, look at that! Oh, there's a big boy! Oh! NARRATOR: Now, a team of shark scientists from Florida International University are setting out on a mission to find a record-sized hammerhead. ERIN: It's really important that we're able to find these really large great

hammerheads because they're such important apex predators. NARRATOR: Their expedition will see them exploring part of the migration route of these giant sharks from the bridges of the Florida Keys to the shark-filled waters of the Bahamas, doing whatever it takes to come face to face with the world's biggest hammerhead. DEMIAN: It's coming to the surface fast. ERIN: Oh, that's a big one. DEMIAN: It's a monster. ERIN: Whoa! CANDACE: Whoa! NARRATOR: The team starts their expedition in the Florida Keys, a place famous for giant hammerhead sightings and an important location on the great hammerhead migration route. DEMIAN:

South Florida is a known pupping ground for the great hammerheads, so it stands to reason where there's pups, their mothers should be at some point when they come to give birth. So, this is a good spot to look for them. YANNIS: This is an area well-known for large great hammerhead sharks. There's some big bridges with lots of water flow underneath. So, our chances of catching them here are pretty good. DEMIAN: So, We're trained to catch a really large hammerhead shark so that we can put a bio-logger on it. We've already tagged and got information on

small ones and medium-sized ones, but the big ones are sort of the Holy Grail for us. We don't know exactly what the maximum size is of great hammerheads. They're very, very large, very difficult to catch and measure. YANNIS: There have been reports of some individuals that may have been in excess of 20 feet. Now, how accurate those are, we don't know. DEMIAN: This great hammerhead was actually caught in Florida by a recreational angler, and it actually is the heaviest and biggest great hammerhead shark caught in the entire world, and it was donated for scientific research.

So, they actually learned quite a bit because it's very rare to obtain a specimen of a great hammerhead of this size. This is very nearly as big as they get. It was 14.5 feet long and it was 1282 pounds. Could you imagine another six feet added to this already enormous shark and the amount of weight that would be added with that? It must be hundreds or even maybe a thousand pounds. So, that would be an impressive animal to see for sure. YANNIS: A six-foot hammerhead will have a very different ecological role compared to let's say

a 14-foot hammerhead. So, our goal here is to get the larger-sized range, those larger animals, and try to understand what role they may be having on the ecosystem. NARRATOR: To catch a large hammerhead, the team will first need to figure out where a giant could be hiding. A needle in a giant, blue haystack. DEMIAN: Great hammerheads are actually quite difficult to locate. So, Yannis and Erin are gonna go scuba diving around some of the bridges, where hammerheads have been seen. And Candace and I are gonna go drop some baited remote underwater video cameras to sort

of provide some intel on where they might be. YANNIS: We're at the bridge now. So, I think we'll go and take a look and see if there are any sharks, any hammerheads obviously specifically, but also see what other species of sharks are there. I'm not sure what the visibility will be like. Sometimes it's pretty murky around here, so fingers crossed it's not too bad. This is also a spot, you get really strong tidal currency here, so that basically means we gotta keep this short. Tidal currency can get really strong, which makes it unsafe, especially if

the visibility is low, which often is under the bridge. ERIN: So, we'll just drop down, take a look around, and then if the current is kind of ripping, we can just head right back up. YANNIS: Yeah. These bridges are great places with lots of current flow, so that tends to be a place where you get aggregating fish and that includes prey items of hammerhead like tarpon and spotted eagle rays. So, as with all predators, hammerheads are gonna go to locations where they have a good chance of finding prey and that makes bridge areas likely an

attractive location for them. One, two, three. We don't want to be diving in very strong currents when you have these structures and objects that you could hit under the bridge. ERIN: Hammerheads start off at just a few feet long and then they can grow to really large sizes, and that's why it's really important that we're able to find these really large individuals because it gives us this better picture as to how they use energy and how their speed changes and their behavior changes throughout their lifetime. DEMIAN: One of the reasons we study great hammerheads is

because they are under serious threat. Many sharks are fished for their fins which are used in shark fin soup, but the absolute pinnacle is the fin from a great hammerhead. It can fetch a thousand dollars a kilo. So, that has made these great hammerheads a big target and we really need to get that under control so these magnificent predators remain in our oceans. Yannis and Erin are at the bridge right now checking stuff out with their eyes, but we're gonna set some of these cameras. So, what's the plan? CANDACE: We have five of these frames

and we're gonna set them kind of along a nice straight path here using our randomly generated locations. We'll drop her down, after about an hour, we'll come back, pick her up, reset, and continue doing that for the day, and then hopefully tonight, when we look at the video, we'll see that we actually came across a hammerhead. DEMIAN: Oh, perfect. That sounds great. Let's do it. CANDACE: BRUV, or Baited Remote Underwater Video station, is a really great tool for us. Alright, let's do it. DEMIAN: Okay. CANDACE: We'll be able to put down a couple of BRUV

units and see, yes, this is indeed a hot spot for hammerheads. DEMIAN: Right. Good? CANDACE: Yep. That can help us determine where we want to fish for the large hammerhead. DEMIAN: Alright. CANDACE: Alright. DEMIAN: Let's get the next one. CANDACE: Well, this is a pretty sharky area, so fingers crossed we've got some good stuff. DEMIAN: Yeah, sounds good. ERIN: We got in, the current was quite strong, the visibility was awful, honestly. So, there's no sense wasting time on something that's not gonna be valuable for us, so we called the dive pretty early. YANNIS: This is

a well-known sharky spot. They see big hammerheads there. To be honest, a huge hammerhead could have gone past us and we've had no idea, so. ERIN: (Laughs) Oh! Did you see that ray just fly out of the water? YANNIS: We did the dive, and the visibility was terrible. It was almost zero visibility. So, doing underwater survey just fairly pointless. However, while we were there, we did see jumping eagle rays, so we know that prey are there, which means, again, the chances of a hammerhead there should be pretty good. So, it's still worth our time to

go and fish there and see if we can catch a really big shark. NARRATOR: After being left for a couple of hours, Demian and Candace head out to retrieve the BRUVs. DEMIAN: Alright, let's bring them back up. Let's do it. CANDACE: Okay. DEMIAN: Now we've done the boring bit by setting these BRUVs, but now we get to go back to pick them up. CANDACE: Alright, here it is. DEMIAN: Yup. CANDACE: Sweet. Watch out for the camera. DEMIAN: Yup, still going. DEMIAN: (Grunts). CANDACE: Got it? DEMIAN: Still running? CANDACE: Uh. Yep. DEMIAN: Sweet. CANDACE: Boop. DEMIAN:

Pull it up. CANDACE: Alright, here it is. DEMIAN: Which number is this? CANDACE: This is the last one. DEMIAN: Oh, sweet. Okay. Is it recording? CANDACE: Yep. DEMIAN: Sweet. Alright, set it down. Alright, let's go home. CANDACE: Let's do it. DEMIAN: Okay. CANDACE: Whew, hammerhead, hammerhead. NARRATOR: Demian and Candace won't know if they are successful until reviewing several hours of underwater footage. The BRUV footage caught several species of sharks including tiger sharks and a nurse shark. DEMIAN: It's really cool reviewing the footage because we got sharks. But, not only that, we got the one we're

looking for. It looks like it's a juvenile great hammerhead. And where there's pups, there's big females coming here to give birth. DEMIAN: For sharks and definitely for great hammerheads, the females are the larger of the two sexes, much larger. The reason probably is because they gestate their young and so they have to put on a lot of weight, have a lot of energy reserves to carry those offspring. What's really cool about seeing a juvenile is it might not be that the big sharks are right where the BRUVs was set, but it's good evidence they're just

in the general area. Now that we have some good idea of some spots to fish, we're gonna get our gear and head out. YANNIS: Where should we put this? CANDACE: This is a two-person I think. YANNIS: We're gonna start off by trying to fish under the bridges. So, we're going to be on a boat with Val and Jack. We have a team very experienced with fishing for sharks including large sharks. So, if we catch one, we'll be able to tag him. We'll just have to be able to find those sharks. DEMIAN: Yeah, I think we'll

be able to get one by lunch. YANNIS: Well, we only have two days of fishing. DEMIAN: Yeah. ERIN: We've done it before. There's really not a lot of data out there that looks at the speed and acceleration of great hammerheads. This is something that's quite new and so each data set that we get really furthers our understanding about the fine scale movements of this animal. DEMIAN: Is there a tag ready for deployment? ERIN: Yeah, I can actually show you the one we brought. DEMIAN: Yeah, let's see it. ERIN: We have this really cool piece of

technology that actually attaches to the hammerhead's dorsal fin and allows them to collect the data for us. As the shark swims along, it gets speed, acceleration, magnetism, depth, and temperature. DEMIAN: Okay. ERIN: In the video logger, we can see what the shark is seeing. Of course, this type of tag captures so much data, it can't transmit remotely. So, we have to go physically go back and retrieve it. NARRATOR: Here in Florida, the team's goal is to get a bio-logger on a record-sized hammerhead shark. But, with bad weather approaching, they only have a 48-hour window. CANDACE:

Okie-dokie then. JACK: Go. ERIN: I'm ready to fish. YANNIS: And then we can start to getting the drum lines in the water. NARRATOR: With two potential fishing grounds identified, the team decides to start at the Bahia Honda bridge, where Yannis and Erin spotted potential prey. YANNIS: Drum lining is a good system when you really want to sort of minimize the amount of time that an animal is on the line. It's simply a weight attached to a float going to the surface, and a hook leading off of it with a lot of leader, so that if

a shark does take the hook and gets hooked up, it can actually swim in large circles, it's never prevented from swimming. That's really important for the safety of the animal. ERIN: Ready? JACK: Go. ERIN: We don't want a single animal staying on that line for too long because that can be stressful. And, fortunately, we have this technology, called a Hook Timer that actually shows us how long that animal has been hooked. VALERIE: So, when the shark comes, you can pull on it, but it's not gonna pop unless it's really forceful. And it's a magnet. CANDACE:

Alright. We're in there? ERIN: Ready? JACK: Yeah. CANDACE: Ready? Mark. VALERIE: Mark. CANDACE: Weight's in. NARRATOR: The team sets out eight drum lines and then checks each one every 30 minutes. YANNIS: Wait for it, wait for it. CANDACE: (Laughs). YANNIS: Mark. ERIN: Clear. YANNIS: So, after this, we'll go and check the other ones. ERIN: Okay. YANNIS: 'Cause they've been out for over 30 minutes, some of them. CANDACE: When we're checking these drum lines, it's mentally and physically taxing. ERIN: Creeping up on it. CANDACE: Coming up to the buoy, grab the buoy, pull in the lines,

check if there's bait. ERIN: Bait on, but not even a nibble. CANDACE: And do it all again. JACK: Next one. ERIN: Bait on. It looks good. CANDACE: Grab the buoy, pull in the line, check if there's bait, do it all again. JACK: What do we got here? ERIN: Nothing. Nothing is on here. CANDACE: And to do that with no success for what you're going for? It takes a lot of mental and physical strength. ERIN: It's just non-stop the entire day, just checking these drum lines over and over and over. With, hopefully, breaks where you've got

a shark on and then you actually get to work up that shark. JACK: That buoy looked weird. DEMIAN: That buoy looks weird alright. It's bobbing too. Yeah, it just went under. Yeah. ERIN: Good signs, good signs. CANDACE: Come on, shark. (Grunts) There's definitely some resistance. Yeah, something's on it. Really, nurse shark? DEMIAN: The most common species we will get in Florida is probably gonna be a nurse shark. NARRATOR: And, disappointingly, a nurse shark is exactly what they have on the line. There's little scientific data the team can get from one of the most familiar sharks

in the area. DEMIAN: We feel immense disappointment because that's not what we're after and they're difficult to deal with. Alright, let's go to the next. CANDACE: On to the next one. JACK: You all set? ERIN: Ready. CANDACE: Yeah. JACK: Alright, hang on. NARRATOR: The team checks the lines for over eight hours but has little luck. CANDACE: Does it feel heavy? ERIN: Kind of. DEMIAN: It's a nurse shark. CANDACE: Argh! JACK: Is it really? DEMIAN: It's a nurse shark. YANNIS: Oh, my god. DEMIAN: Shocker. Nurse. CANDACE: Boo! YANNIS: Open your mouth. CANDACE: Yes. ERIN: Whew, good

job. DEMIAN: Nice. DEMIAN: We spent one day at Bahia Honda Bridge and all we've got to show for it is sunburn and two nurse sharks. Hammerheads are rare. What can you say? We're gonna call it quits and, tomorrow, we're gonna try out some spots that were recommended to us. We've really only got one fishing day before the bad weather sets in and we are benched, so hopefully these spots pan out. NARRATOR: The next morning, the team is back at it again and it's not long before they start seeing sharks. JACK: Okay. Ready? ERIN: Yep. DEMIAN:

This spot was recommended to us by a colleague who does a lot of fishing for sharks and rays down here and he's caught plenty of hammerheads. JACK: Coming up! ERIN: Feeling optimistic. VALERIE: Got it. -Timer. JACK: Yeah, pull that weight up. YANNIS: Oh, there's a shark. ERIN: All right. DEMIAN: Oh, that's a blacktip. CANDACE: That's blacktip? YANNIS: That's blacktip. CANDACE: That's a blacktip. DEMIAN: Oh, let's tag it. Someone wanna get a tail rope ready? CANDACE: The really great thing about shark fishing is that even if we're targeting one species and we catch another, we can

still utilize data from that animal. DEMIAN: It's a female. JACK: Got it. CANDACE: And we take genetic samples. Got it. Just a small, little fin clip can tell us tons and tons of information and unlock huge avenues for us to study. DEMIAN: When we catch a shark, we're like a pit crew. We have to be quick. So, everyone has their job, and we try to do things as quickly as possible. NARRATOR: To avoid getting bitten and to keep the shark relaxed, the team flips it upside down, putting it into a hypnotized state called tonic immobility.

YANNIS: What is important to realize is that sharks are all muscle. So, even a small shark can cause considerable damages if someone was to get bitten. DEMIAN: Alright, who's ready? ERIN: I'm ready. CANDACE: BCL 95 fork 109. YANNIS: Somebody do the pecs? CANDACE: Okay. DEMIAN: Do you want me to do the tail? ERIN: Yeah, sure. DEMIAN: Do you guys want to de-hook? CANDACE: Okay. JACK: Okay. CANDACE: Ready? DEMIAN: Turn. ERIN: One, two, three. (Laughs). ERIN: Okay. DEMIAN: Alright, nice. CANDACE: Good work, team. YANNIS: There's actually a few species of sharks that I would consider true

apex predators, meaning they're at the top of the food chain. Great hammerheads may be one of the exceptions, especially those big adults, and these are also shark killers. Great hammerheads like to eat other sharks. So, sharks would often feature in their diet. DEMIAN: Blacktips are absolutely potential prey for these great hammerheads, so the fact that they're around suggests predator may be as well. NARRATOR: Every winter, great hammerheads await one of their biggest hunts of the year. Tens of thousands of blacktip sharks migrate up the coast of Florida in search of warmer waters. Only the safety

of numbers and shallow waters can help them evade this apex predator. JACK: We've got two more, guys. ERIN: Two more chances. We just need one. CANDACE: Oh, oh, oh. She's vertical. JACK: You guys got it? YANNIS: Yup. DEMIAN: Yeah, he's got it. CANDACE: Okay. JACK: Good man. DEMIAN: This is good. It's coming up. DEMIAN: It's coming to the surface fast, so we might be good. I see a shadow. I don't see the shark yet. It's big. Holy (bleep), it's big. ERIN: Oh, that's a big one. DEMIAN: That's a monster. CANDACE: Whoa. ERIN: Holy. DEMIAN: That's

a monster. CANDACE: Whoa. ERIN: Holy cow. Oh, that's a big one. CANDACE: Oh. DEMIAN: No, tiger. CANDACE: It's a tiger. DEMIAN: Tiger shark. ERIN: Tiger. YANNIS: Definitely a feat. CANDACE: Yup. DEMIAN: Sharks are just one big muscle. They are so much more powerful than us. CANDACE: Oh, she's wrapped. Hold on. Her face is wrapped on the mono. Yeah. (Grunts). YANNIS: Just got to spin her. Pull her towards you. CANDACE: When you're controlling all the weight of that shark, it's putting its full force against you. It takes almost everything you have in you to fight that

animal. You really have to be physically ready to take on that battle. You know, in reality, you should probably lose because you're sometimes fighting over a thousand pounds of weight. YANNIS: Although it looks dramatic, we keep it to a minimum. With these large animals, you could get a really bad bite. Obviously, nobody wants to get bitten, so our two priorities are our safety and the shark's safety. So, we have to work really quickly to get it processed and released as soon as possible. CANDACE: Yeah. Oh, that was helpful, that was helpful. Whoa, she's really wrapping.

YANNIS: There's really very little we can do to fight that strength. So, we really have to kind of use strategy as well to get these animals under control. If we try to go strength against strength, we're gonna lose. ERIN: She's really, I'm not giving it. CANDACE: Head. YANNIS: Pull. DEMIAN: And tail. CANDACE: Head. YANNIS: Got it? DEMIAN: Yep. YANNIS: Be careful. Don't pull it. Oh. CANDACE: Whew. DEMIAN: We got it. CANDACE: Completed. DEMIAN: Yeah, she's gonna chill. She's gonna chill. YANNIS: Just trying to get her calmed down. We've got this shark up to the surface.

She had a lot of energy still, so she got pretty active. So, it's been a little tricky controlling her but now we have her on her back which will kinda put her on a trance-like state. So, she'll go into tonic immobility. It only takes a few minutes and she'll start calming down, eventually. CANDACE: I think she's calming a bit. DEMIAN: Yeah. CANDACE: She's feeling looser on my end. DEMIAN: She's slowly calming. Can you give me the DNA tool? ERIN: It's not every day that you get to work up an 11 or, or 12-foot tiger shark.

CANDACE: Yup. DEMIAN: Alright, we've got a DNA sample. ERIN: And even though we were looking for hammerheads, we collected genetic samples and took measurements, and all of that goes to our understanding of tiger sharks and other species of sharks as well. JACK: Definitely, we can release that. YANNIS: Pull with your elbows. There you go. CANDACE: Yes. YANNIS: You can take the tail rope. DEMIAN: Off. YANNIS: Good? DEMIAN: Yep. CANDACE: She's swimming the other way. DEMIAN: Alright. You ready for the shot? CANDACE: Oh, she's coming. Here she comes. YANNIS: So, weather's getting pretty nasty. So, I

think we should get out of here. DEMIAN: Yeah, I don't see getting a camera tag out. YANNIS: I think we just call for it today. DEMIAN: Yeah, let's call it. JACK: No, no, no, we still got one more. Line's coming up. Looks like there's something there. Buoy's moving all over the place. CANDACE: That buoy's really upright. DEMIAN: Yeah. CANDACE: This could be the one. DEMIAN: Did you see full body out? YANNIS: No, I just saw a splash. DEMIAN: Okay. Oh, it's for real. That could be a big hammerhead. JACK: Oh, yeah? Ooh, okay. ERIN: Oh.

CANDACE: Hello, darling. DEMIAN: Oh, yeah. CANDACE: She's swimming. She's swimming. YANNIS: Oh, something jumping now. -Okay. ERIN: There we go. YANNIS: Three. ERIN: Three. CANDACE: Good. YANNIS: Is it still on? ERIN: I don't think there's anything on here. DEMIAN: Oh, no. JACK: Really? ERIN: Yeah. JACK: That timer's not hot popped? CANDACE: It says five minutes. ERIN: No, no more tension. I think it's off. Shoot. DEMIAN: What, it's gone? ERIN: And we got no bait and YANNIS: No hook. CANDACE: No hook. ERIN: Oh. DEMIAN: Straight hook. ERIN: Straight. DEMIAN: Get that on camera. CANDACE: That was

a big (bleep). ERIN: Straight hook. YANNIS: Straight and snapped. ERIN: Look at that. DEMIAN: Oh, wow, look. ERIN: That's some serious pressure. Man, I haven't seen that. YANNIS: When we're bringing the line, we clearly had a shark on the end of the line. The line was going up to the surface, which is often what hammerheads do when they get hooked up. So, I gotta say, I was pretty hopeful that time, but, unfortunately, whatever was on this, snapped and straightened the hook. There was probably something really big on the end of that. CANDACE: That was a

hammerhead. ERIN: (Laughs) Dang. VALERIE: Holy cow. YANNIS: That probably was the biggest hammerhead in the world. ERIN: Well. CANDACE: That was a beast. Oh, that was the one. YANNIS: Those are some decent-sized stainless-steel hooks, so it takes a pretty big animal to be able to straighten it out and to snap it. DEMIAN: Yeah, that was the last one, the last shot. CANDACE: We had it, until we didn't. ERIN: We're gonna have to keep this, even if we don't find the world's biggest hammerhead. YANNIS: Yeah, you should keep that. DEMIAN: Yeah. ERIN: We should keep this

as a maybe. (Laughs) DEMIAN: Yeah, right? ERIN: So, at the end of the day, we didn't catch the hammerheads that we were looking for, but, honestly, that's the way the field work goes. YANNIS: These are not animals that are usually abundant. DEMIAN: Yeah. YANNIS: So, it's always a numbers game whether or not you're going to catch one. I mean, no doubt this is a sharky place. It's just that if they're not gonna beat the tigers and the nurses to the punch and take the bait, we're not gonna get 'em. It's gonna be a question of

effort and luck. ERIN: Well, we put in the effort today, we just didn't have any of the luck. CANDACE: Yeah. NARRATOR: While the team came up empty handed in Florida, their quest to find the largest great hammerhead isn't over just yet. DEMIAN: We actually got some interesting intel from the Bimini Shark Lab, the place where I started my career two decades ago. They actually saw the biggest hammerhead they've ever seen at their dive site last year. So, it seems like a good spot to check out. ERIN: The reason that we don't know a lot about

great hammerheads is because they're hard to study. So, the only way that we're gonna get this data is just by continuing to go out and be on the field as much as possible and eventually we will get there. DEMIAN: One thing we do know about hammerheads' movements is that they go back and forth between Florida and The Bahamas, and some of them are definitely coming from this region. So, that could be why we're not seeing too many here in Florida because some of them have gone to The Bahamas. And that's where we're headed next. ERIN:

So, it was about this time last year that the Shark Lab encountered the largest great hammerhead that they have on record. Which is saying something, 'cause they've seen some pretty big animals. Any great hammerhead sighting would be spectacular, but it would be great to be able to see it for ourselves. CANDACE: I'm from The Bahamas and any opportunity to do work in your home country is something to be really excited about. The entirety of our waters are a shark sanctuary, so sharks are very, very safe in our waters. The Bahamas is one of the best

places in the world for sharks and also, specifically for hammerhead sharks. NARRATOR: The team is meeting up with the head of the Bimini Shark Lab to learn more about their sighting of a giant. MATT: We're kind of early in the season right now. It's just starting to kick off, so we've been out for the past few weeks actually looking who's around. The Shark Lab's been here for 30 years. In the lifespan of the Shark Lab, the hammerheads are a relatively new study, but, even saying that, they've now been studied by the Shark Lab for over

a decade. So, close to 12 years we've been actually identifying individuals here. DEMIAN: I heard that you guys saw a really big hammerhead last year. The biggest one you've ever seen. MATT: Yeah, we were out doing one of our just normal dives and we had, I don't know, five or six different hammerheads, and, all of the sudden, we just see this massive one kind of come through the pack and she just came right through the middle and made all the other hammerheads, our normal ones, look relatively average. We have some photos of Queen, who is

the new biggest one next to Gaia and she actually kind of makes Gaia look like an average shark, which, once you see Gaia in the water, that's pretty impressive that she can make her look that small. ERIN: That's amazing. DEMIAN: That's crazy. So, a great, great hammerhead. ERIN: (Laughs). MATT: And we're only looking at probably the subset that are actually at the dive sight. So, we think that there's other residentials that are just around the island doing normal hunting behavior, chasing stingrays, eagle rays whatever is in. The photo ID is really only the ones that

come to that provisioning dive site here in Bimini. YANNIS: So, it seems like you have almost sort of two groups of sharks. You have some that are gonna be residential and hanging around the feeding site and others that are ranging more widely around the island. So, maybe we should split into groups and half of us will go to the feeding site and then the other group can go and sort of drive around and see if we can get some of those more wider-ranging individuals. DEMIAN: So, you all go there. How about we go to Turtle

Rocks? This is where I saw the biggest hammerhead I've ever seen in Bimini two decades ago. And we can work our way along those islands and check out the flats and stuff. Places where there's a lot of food for them. MATT: Yeah, sounds like a really good plan. ERIN: Sounds good. DEMIAN: Sounds good. ERIN: You guys got everything you need? DEMIAN: Masks and snorkels, snacks, check. CANDACE: That's not your snorkel. YANNIS: Our plan is to split into two groups. Myself and Erin are gonna go to the dive site and dive there, which is where they

regularly see the great hammerheads, and our hope is that we see one of the largest species and perhaps see Queen. Candace and Demian, on the other hand, are gonna go to some of the sites where we know some of the hammerhead prey items are found. Stingrays and eagle rays. So, it's always good if you wanna see a big predator, go, and hang out in the area where you know their prey can be found. DEMIAN: Okay, well this is the spot where, 20 years ago, I saw the biggest hammerhead I've ever seen. It was right there.

We were driving the boat past and we saw this eagle ray jumping up out of the water. And, normally, they're quite graceful, but this one was distressed. It was jumping in sort of a weird way. And then, all of a sudden, there was this big explosion of water and I saw the tail of the shark come out. And, so, of course, I was 22 years old, I got the mask and snorkel and jumped in to see what was going on. I see the eagle ray on the bottom disabled. It's got a big bite out of

its wing and all of the sudden I hear everybody start screaming on the boat. Last thing you wanna hear. Because, I don't know about hammerheads. I don't know how aggressive they are, what the deal is. So, I look down and this gargantuan hammerhead is coming up from the bottom and, you know, their heads are just getting wider, wider, wider, and I'm, like, backing up. But the thing turns, and I see her eye just sweep over me, take a look, and she clearly didn't think I was a threat, didn't think I was a competitor, and then

she went back, and she just ate the eagle ray right in front of me. DEMIAN: It was an incredible thing for anybody to see. So, with any luck, we'll see a big hammerhead around here. IF we're extremely lucky, we could hit the jackpot twice in 20 years and see a predation event like that. CANDACE: That would be really cool. DEMIAN: Yeah, let's go check it out. CANDACE: Let's do it! NARRATOR: While Candace and Demian snorkel the potential hunting ground in search of a giant, Yannis and Erin have been waiting without much luck. YANNIS: Well, the

nurse sharks are here. ERIN: We've been sitting here at this spot for a couple hours now and the only sharks that we've seen are nurse sharks, which are great, but that's not what we're looking for. YANNIS: Well, right now, the water's unusually warm and sharks are sensitive to water temperature, so they may just not like these warm waters. Even though we know there's plenty of hammerhead sharks in the area, getting them to the boat is still a little bit tricky. So, we're gonna go do a dive anyway, just test out the gear, the lasers, the

camera with some nurse sharks , which are always in the area, Matt is gonna go down start baiting in these sharks , and then, fingers crossed, the hammerheads will turn up. ERIN: Yannis' gonna have a camera so we can do some photo ID, and then I'm gonna use some lasers to actually measure how large some of these animals are. YANNIS: After a really slow start, we finally had some really great action. YANNIS: Matt is baiting. He's got a lot of experience baiting in these sharks. Erin's gonna use the laser photogrammetry to try and get some

size estimates. I'm gonna be just taking pictures because the Shark Lab keeps a photo ID that can identify individuals just from that photograph. ERIN: The tricky part about laser photogrammetry is they have to swim by you just right so that those lasers hit perpendicular to the shark. And sometimes that means it takes a couple tries as they swim by. NARRATOR: The hammerhead is a resident male named Atlas, measuring 11 feet long. No giant, but a good sign more could be around. NARRATOR: As the hammerhead leaves, a new shark arrives, a tiger shark. NARRATOR: But just

as quickly as the tiger shark appears, something has scared it off into the distance. NARRATOR: While the dive team waits in hopes of a giant, Dr. Demian Chapman and Candace Fields continue their search in the wild hunting grounds and have discovered a hammerhead buffet. DEMIAN: Here's a spot I wanna check out that I've never been to. It's called Honeymoon Harbor. I've heard there's a big concentration of stingrays there. I've also heard great hammerheads have been seen dashing in there and chasing the stingrays. This is crazy. I've always wanted to see this site. They didn't have

this when I was a staff member at the Shark Lab years and years ago. Whoa, he just nipped me! CANDACE: What's so great about The Bahamas is not only that it's a shark sanctuary, but they also have an abundance of reliable food. I mean, just look at where we are. DEMIAN: So, if you want to find a predator, the best way to do it is to find its prey. Great hammerheads hunt things like stingrays, I've heard of them taking out dolphins, and they also eat other sharks, so that really puts them at the very top

of the food web. This is crazy. There're so many southern stingrays. CANDACE: These are really closely related to sharks. Some people call them "flat sharks". In the same group, they're all elasmobranchs, and they have lots of similar characteristics. DEMIAN: And we've got one right here that has no tail and a bite in it. I mean, it's not a big shark bite, but it's definitely some damage. You don't have to actually spot the shark to know that it's around. So, that's pretty good evidence that the sharks around here are definitely preying on stingrays, so this is

super cool. CANDACE: Sometimes when you see these hammerheads, even though they're these huge predators, you see actually lots of marks which are seemingly markings from stingrays, so it's clearly quite a battle that goes down. And it's not just a full-blown hammerhead takes the win. DEMIAN: Definitely. I mean, I think the record is something like 55 spines in the mouth of a hammerhead from eating all these stingrays. And then I've heard of a hammerhead that was still alive and it had a stingray spine in its heart, which is just crazy. CANDACE: Wow. DEMIAN: It's definitely a

difficult meal. It's not something that's easy to get. Having seen predation by a great hammerhead, I can tell you firsthand they are very, very capable hunters. And they are always on. Like other sharks, a lot of times, they're not in hunting mode. Hammerheads, always seem to be in hunting mode. I feel like I'm gonna be prey in a second 'cause these are pretty hungry flat sharks. Let's go check out some other spots around the island and see what we see. Sound good? CANDACE: Sounds good. NARRATOR: With evidence of a recent attempted predation, Candace and Demian

head to a new location with a change of tactics. But back at the dive site, something has scared an adult tiger shark away. ERIN: After all of that waiting, everything kind of happened all at once. First, we see a male that we identified as Atlas, and we saw a tiger shark. NARRATOR: Erin finally manages to get a measurement of 13.1 feet. It's a shark named Gaia, just 18 inches shy of the official world record. ERIN: It might not have been the world's largest hammerhead, but she was certainly large and definitely larger than what we've seen

in our study off of south Florida. ERIN: Seeing Gaia and actually having her come so close that occasionally I had to duck a little bit is just an incredible experience. YANNIS: As a shark biologist, it always gives me hope to see animals this large. Because, obviously, a sign of a healthy system is not just that you see sharks but you're seeing larger sharks. If you're only seeing smaller animals, that's a warning sign. So, seeing these truly large, near-maximum-size sharks is a great sign. ERIN: Waiting for hours and hours, not sure if we were gonna get

anything and then to have those two hammers in just within 20 minutes, I mean, it made it all worth it. YANNIS: Yeah, that was spectacular. Worth the wait. NARRATOR: On the other side of the island, Candace and Demian are changing tactics and going with a more high-tech approach. DEMIAN: Hey Candace, is that thing ready? CANDACE: Yeah, just about. DEMIAN: I'm old school, used to snorkeling around and diving and looking for sharks, but Candace is a great drone pilot. We're right behind the Shark Lab, there's plenty of stingrays. A lot of life out here, so I

could well think we could see a big hammerhead out here. CANDACE: Okay, cool. DEMIAN: So, what do you think we could do with a drone survey? CANDACE: I think we can do like a transect around here. Do you mind holding this for take-off? DEMIAN: Launching this? Yeah, why not? CANDACE: Alright. Doing drone surveys gives us a whole another dimension to our research. When you're underwater, you can only get so much visibility in front of you, above you, below you. But when you get that aerial view, you can see so much of what's going on. DEMIAN:

Really clear. CANDACE: Yeah. DEMIAN: That's beautiful white sand. Makes it so easy to see stuff. CANDACE: We're lucky here in The Bahamas. The water is so nice and crystal clear you can see everything perfectly, especially when you get a nice, calm day and the water is just glass. It almost looks surreal that you're seeing this clear picture of these animals from a camera. Even this height, you can tell if something's swimming. DEMIAN: Yeah. You're pretty good at this. CANDACE: Yeah. (Laughs). DEMIAN: I think you know what you're looking for. CANDACE: Often, you use a drone

to do things like a transect survey and you basically just set two points, point A and point B, and you run your drone between them. And you can look at how animals are responding to the drone. And you can get a rough estimate on size of animals. You need pretty great conditions so that you can see clearly. The depth has to be just about right so that you're not getting refraction of the light and, so, it can be challenging at times to use the drone. But it's something that I think is going to be huge

tool in science in years to come. CANDACE: I think I see a turtle. DEMIAN: Oh, let's check that out. Do you think that turtle knows? CANDACE: I think it knows, 'cause it sped up. When I lowered, it sped up. DEMIAN: Definitely speeding up. CANDACE: You can understand how many species are in an area. Whether that's all sharks, whether that's sharks and their prey. Alright so I think right there is a stingray, probably a southern. DEMIAN: Okay, yeah, I see what you're saying, yeah. CANDACE: Yeah, definitely a stingray. DEMIAN: Okay, that's cool. CANDACE: Oh, I think

I see a shark here. DEMIAN: Oh, serious? Oh. CANDACE: Yeah, a lemon shark, I think. DEMIAN: A lemon shark? They definitely hunt the stingrays just like the hammerheads do. So, that's a good sign there could be hammerheads about. Yeah, that lemon shark is just sort of hanging out in that seagrass patch. CANDACE: Yeah, I'm sure it's probably looking for some food in there. DEMIAN: Might be trying to flesh some prey or something. Yeah. CANDACE: Looking at what type of habitat these guys are using, whether they're in the flats, are they going into deeper water? I'm

not seeing any hammers over here, so I'm gonna try to head over to some deeper water and maybe with a little bit of luck, we'll see one. DEMIAN: That sounds like a plan. What's that? CANDACE: That's definitely a hammerhead. DEMIAN: Oh, man, that's a great hammerhead. That's so cool! We got it. CANDACE: Now we're cooking. DEMIAN: Oh, here we go. Yeah, this is what we want. CANDACE: (Laughs) This is what we came for. DEMIAN: We got it. We've got it. It's not a real big one. Nicely done. CANDACE: So, we did see a hammerhead on

the drone. But, unfortunately, because of the depth of the water where we saw it we couldn't get an exact size. It doesn't look like it's a very big one, but it's undoubtedly a great hammerhead. Even though we couldn't get a measurement, it's still super exciting to just be able to find what we're looking for. These guys are not the easiest to come by. Even when you're in Bimini sometimes you have a tough go at it. So, it's really exciting to just even find one. And, for me, it's super exciting because it's the first time I've

seen one in its natural habitat. You can definitely tell it's a, it's a great hammer. DEMIAN: Yea, for sure. That's really cool. CANDACE: Alright, so the battery's getting low, so I'm gonna bring her back in. Coming home. Just because we didn't see the world's largest hammerhead, doesn't mean that this expedition was a failure. ERIN: We still got a lot of other really valuable data from different species. YANNIS: We're really only at the beginning, or early stages, of this project, so we know it's gonna take time. This is gonna be a multi-year project. DEMIAN: It was

tremendous to go see such a healthy population and big, big animals. ERIN: Honestly, I work on these species and, still, every single time I see one face to face, it just reminds me why we need to continue studying this critically endangered species. KORI: Watch out, watch out! ANDY: Whoa! NARRATOR: A giant tiger shark. KORI: She's the biggest shark I've ever seen. NARRATOR: Maybe the largest tiger ever. KORI: Oh! NARRATOR: And she has friends. KORI: They all go vertical together underneath. Multiple approaches at the same time. NARRATOR: Now... ANDY: Let's do it. NARRATOR: To find out

why she's so big... ANDY: Lot of sharks here. NARRATOR: Are there more like her? ANDY: You and Pierrick were literally dancing on tigers. NARRATOR: And unlock the mystery of what may be... ANDY: Get on the boat. NARRATOR: ...the world's biggest tiger shark. KORI: Woo! ♪ ♪ NARRATOR: 2006. French Polynesia bans shark fishing in 2 million square miles of the South Pacific. Now, 14 years later, these waters bustle, a vibrant sharkopolis. ♪ ♪ ♪ ♪ More than 20 different species. ♪ ♪ Here... tigers rule. These apex predators are the deadliest sharks in the world after great

whites. In the last decade, tigers have killed more than a dozen people worldwide. But here in French Polynesia, the government welcomes these sharks. More and bigger tiger sharks appear in French Polynesia every year. Marine biologist Kori Garza thinks marine protection is changing the tiger population. KORI: Tiger sharks are apex predators, and their presence is a good indicator that the population is thriving and the ecosystem as well is thriving. NARRATOR: It's become a magnet for monstrous sharks. One mega shark in particular may be the largest tiger shark alive. Nine months ago, Kori filmed this female here

and named her Kamakai. KORI: We have seen some really, really big sharks, but none quite like her. NARRATOR: Male tiger sharks can grow to a whopping 13 feet. Females? Even bigger. And Kamakai? She's off the charts. KORI: When we first met Kamakai, it was really unexpected. I've been diving with tiger sharks in multiple countries, and she's by far the biggest I've ever seen. The smaller sharks took a, took a back seat to her for sure. NARRATOR: Kori is 5-foot-8 without her fins. Based on that, Kamakai is more than 16 feet! How much more is hard

to tell. But 18 feet would be a new record. She could be one of the longest tigers ever filmed. But it's her girth that truly sets her apart. KORI: It's not just her length, but her width as well. She can be 5 meters long, but when she's like 3 meters wide, including her fins, like, that's insane. NARRATOR: Kori has a theory that something about the Pacific Islands helps tiger sharks become giants. KORI: It'd be really cool to see her again and see what more behavior we can learn from her. It could also give us some

insight into the areas that she's been since the last time we saw her. NARRATOR: Now Kori wants to find Kamakai again and maybe discover the secret of her size. Kamakai may reveal to science what it takes to become a mega shark. ANDY: Okay, here we go. ♪ ♪ ♪ ♪ NARRATOR: Kori enlists cameraman and shark conservationist Andy Casagrande to help search for Kamakai and unlock this mystery. ANDY: She's got to be one of the biggest tiger sharks that I have ever seen. NARRATOR: Andy knows big sharks and knows how to be in the water with

them. ANDY: Bring me the sharks. Whoa. NARRATOR: That's good. This research is all about being up close and personal. But Andy's never dived with the tigers of Tahiti. ANDY: There's only a handful of spots in the world where you get this sort of density of tiger shark action. Super pumped, this is day one. NARRATOR: Less than a mile from the main island of Tahiti is a hot spot known for big sharks. ♪ ♪ KORI: You can see we have sharks here already, just as we pull up. Some blacktip sharks, grey sharks, and hopefully we can

see some tigers here. ANDY: Let's suit up. NARRATOR: Their plan: to take pictures of as many dorsal fins as they can. Like a fingerprint, each is unique. They'll use the fin shots to look for a match with Kamakai. ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ NARRATOR: A sea turtle is a good sign. Turtles are a tiger shark's favorite food. The shell is no protection from a big tiger's bite force and specialized teeth. Tigers eat just about anything and will gorge themselves to capacity in one sitting. They even eat other sharks. NARRATOR: Like this grey

shark. One of the many species making a comeback since the shark fishing ban. ♪ ♪ ♪ ♪ NARRATOR: It's big. But too far away to get an ID shot of the dorsal fin. ANDY: Well, we had one tiger. KORI: Tiger, tiger! ANDY: When you screamed, "Tiger, tiger," I looked and just saw it turning away already, kinda swimming off in the distance. You could see that distinct tail, perfect tiger tail. You could see some stripes. But I saw it with my own eyes, but it didn't register that well on camera. NARRATOR: Scuba gear makes a lot

of noise underwater; the regulators, the bubbles. These truly wild sharks shy away. Andy and Kori decide to free dive using only snorkels. Harder, but much quieter. ANDY: Kori, I'm going to follow your lead, eh? KORI: Yeah. ♪ ♪ NARRATOR: The difference is shocking! ANDY: Wow, there's a lot of sharks here. ♪ ♪ ♪ ♪ I mean, I'm gonna follow you. Anytime you dive down, I'll follow you. Okay? KORI: Ka ka ka ka! NARRATOR: Kori's underwater call lets Andy know there's a tiger shark close by. KORI: Ka ka ka ka! ♪ ♪ NARRATOR: Andy goes after

a dorsal ID shot. ♪ ♪ The underbelly is smooth, no claspers. She's a female. ANDY: Kori, on the next one, if she comes by, can you dive down and try to get closer? KORI: Yeah. NARRATOR: To measure the shark, Andy will use Kori as a comparison. But first, she must get close. KORI: Ka ka ka ka! NARRATOR: Kori is a master free diver. She dives 60 feet deep and holds her breath for up to four minutes. ♪ ♪ ♪ ♪ She makes no noise at all. ♪ ♪ ♪ ♪ Now the tiger comes right in.

♪ ♪ It's bold. ♪ ♪ Maybe too bold. KORI: Ka ka ka ka kay! Ah! KORI: Ka ka ka ka kay! Ah! NARRATOR: A big Tahitian tiger shark goes eye-to-eye with marine biologist Kori Garza. ♪ ♪ ♪ ♪ NARRATOR: Kori must swim close to get a size comparison. ♪ ♪ ♪ ♪ ♪ ♪ She's big, 12 or 13 feet. ♪ ♪ But Kamakai, the female tiger they're looking for, is at least 16! So this is not Kamakai. But she is their first clue. ANDY: Wow! That was incredible! NARRATOR: Another large female tiger shark. It supports

findings that bigger sharks now thrive in Polynesian waters. Tigers are typically loners. But the area is large. Kamakai could be here, too, just out of sight. Andy has an idea. ANDY: What about at nighttime out here, have you ever gone diving at night? KORI: Ah, I haven't gone diving at night here, I wouldn't recommend it, not necessarily particularly the tigers, but just all the sharks. NARRATOR: Tigers use their acute shark senses to hunt in the dark. Kori and Andy may have a better chance of finding Kamakai after sunset when they're move active. KORI: If it's

kicked up a notch at night, it might not be the safest thing to do. ANDY: The thing is I have a way we can actually do a night dive without ever even getting wet. KORI: Well, then absolutely we can do that. ANDY: Alright. NARRATOR: Andy has a piece of equipment made for filming sharks at night. ANDY: This little thing is a little tethered drone. It's called the Gladius Mini. NARRATOR: Andy hopes for a dorsal fin shot that'll identify Kamakai. ANDY: Some of the sketchiest dives I've ever done have been at nighttime, so actually it's kinda

cool that we can send this guy down instead of us. KORI: We've never been here at night, so it's kind of cool to explore on that bottom, see what's hanging out there. We might see something we normally don't during the day. How strong is this thing, like what kind of pressure can it handle? ANDY: Well, to be honest, I have had these things hit by great whites, and they don't really fare very well, so let's just hope we can ID a few tigers down there at night and then bring it back alive. Looks pretty good.

Let's test the thrusters here. (whirring) Alright, sounds a little bit like E.T., eh? Alright, so I'll control it. I'll let you do the honors, throw it in there. KORI: Thank you. Ready? Three, two, one. ANDY: Alright, so give it plenty of slack. And we're gonna unlock and we're gonna head down. Head straight down to the bottom. NARRATOR: Sharks have electroreceptors in their snouts that detect movements made by prey. The electric motor of the underwater drone may also draw them in. ANDY: Whoa, whoa, something's down there. Come check this out. What the hell was that? That

is a big-ass shark. KORI: Whoa, okay, okay. Ho! That's a tiger. ANDY: Woo-hoo. KORI: Oh, my God. NARRATOR: They get their first dorsal ID shot. ANDY: It's like playing a video game with sharks. A live video game at nighttime with sharks. It's kind of cool. NARRATOR: They expand the search area. Then... ANDY: Whoa, another one, another tiger. KORI: Oh, that's a second one. This is sick. ANDY: Okay, it's a female, big female. NARRATOR: It's impossible to gauge length from the drone. But if Kamakai is here, her unique dorsal will give her away. KORI: This is

science! NARRATOR: The shark comes closer and closer. ANDY: That is a big shark. Whoa, I'm gonna stay away from that thing. Look at the eyes on that thing, look at the eyes on her. NARRATOR: Then the shark disappears... behind the drone. KORI: Andy, watch out, watch out! ANDY: Whoa! What was that? NARRATOR: Tiger sharks attack Andy Casagrande's underwater camera drone. ANDY: Something just hit it. KORI: That thing went flying. ANDY: It's going in circles right now. ♪ ♪ ♪ ♪ (bleep) The lights are out. Let's pull it up. We completely-- KORI: There's no, uh... ANDY:

Are you serious? Ah, that's not good. The lights have gone out on this thing. GoPro's still rolling, which is good. But this thing looks like it's dead. Has it got any injuries? Well, at least we got it back. Doesn't seem to be any bite marks on it. But there's definitely some good footage there. NARRATOR: Good footage, and the dorsal ID shot they were after. But is it the giant shark Kamakai? KORI: I have somebody I want to show this to. NARRATOR: Next day, back in the Polynesian town of Papetoai, they visit an expert who IDs

sharks by their fins. KORI: So we were hoping to see if you could look through some of your databases. NARRATOR: Shark scientist Nicolas Buray keeps a photo archive of Tahitian tiger sharks. KORI: That's cool. NARRATOR: And it's been growing. ANDY: How many sharks do you have in your database? NICOLAS: So in our database we have around 55 different tiger sharks. But this is new. For 10 years I saw maybe two only. Right now since three, four, five years, we have more and more tiger sharks. NARRATOR: Local divers send Nicolas dorsal fin shots. He enters them

into the archive and identifies the individuals. ANDY: So you're looking at the stripe pattern? NICOLAS: Yes, the stripe. When the shark is growing, they keep the same stripe. NARRATOR: All of the newcomers are females. Time to find out if they have a match. KORI: This one here is Kamakai, and the dorsal is pretty distinct. She is mature, so there is some scarring. NARRATOR: During mating, male sharks bite the females, which is why female shark skin has evolved to be super thick. Female tigers reach sexual maturity at about nine years. There's no doubt Kamakai has mated.

ANDY: Clearly a big female tiger shark, but do you recognize her? Is she in your database? NICOLAS: No, no, not in my database. ANDY: Oh, okay. NICOLAS: No, this one is, I'm sure I don't know it. NARRATOR: Now they compare pictures from the database with the big females from the night dive. KORI: This is the biggest one that we've seen there. We were thinking possibly the same shark. NICOLAS: No, for me it looks different. KORI: Yup, so this one I think is not the same. NARRATOR: Andy and Kori have just added three new large females

to Nico's growing database. NICOLAS: Do you have the other side? KORI: No. NARRATOR: That makes more than 40 large, sexually mature female tiger sharks, most with dorsal fins chewed up and scarred from mating. ANDY: Looks like just a shredded fin. NARRATOR: Everything points to a tiger shark mating ground. An area with males must be nearby. KORI: So that means there's other hot spots out there, other places where these large tiger sharks are hanging out that haven't been studied yet. NARRATOR: If they can find it, perhaps Kamakai will be there looking for a mate. A fisherman

on another island leads them to the next clue. KORI: He called us and said that he had this crazy, crazy spot where they've had this huge influx of tiger sharks. And that right away caught our attention. His stumbling across this giant population of tiger sharks was something that we absolutely have to go check out. NARRATOR: The spot is 220 miles north inside an atoll; just a few day's swim for a fast-cruising tiger. ♪ ♪ It's the largest atoll in the Polynesian group. A ring of coral reef makes a lagoon 50 miles long, 20 miles wide.

KORI: It's massive, one of the biggest in the entire world, and it's protected, so it's like getting a chance to be in the open ocean, but with a little bit of barrier around you. And there's only two ways to get in and out. ♪ ♪ NARRATOR: Kori and Andy head in with the fisherman who called, Taurama Sun. He's been fishing inside the lagoon for his entire life. And the tiger sharks are new. TAURAMA SUN: We was really surprised to see many, many sharks like this. ANDY: So many tigers. TAURAMA: So many tigers, yeah. NARRATOR: There's

not a lot of tiger shark science from this part of the world. Kori and Andy are the first to investigate here. ANDY: Hey. Wow, looks like we've got at least three tigers right at the back of the boat. There's another one at the front and another one over there. ♪ ♪ NARRATOR: They decide to free dive again. ANDY: Thank you. Got it. ♪ ♪ ♪ ♪ NARRATOR: Tiger sharks are normally solitary. But here they're everywhere. And something about them is distinct. ANDY: Holy smokes! A lot of sharks here! KORI: So many tigers, they are everywhere.

This is amazing! NARRATOR: All of these tiger sharks are less than nine feet; immature juveniles and sub-adults. A very different population to the big females at the first hot spot. Something is drawing younger tigers to the lagoon in large numbers. ANDY: So this thing is just a super basic, non-invasive, spring-loaded fin cam system. NARRATOR: Andy has the perfect tool to find out what's the attraction. ANDY: The idea is to get this right at the base of the dorsal, so that when the shark swims off, you get a perfect alignment with its head. And we're tracking

with it, seeing what it sees, and we're basically diving into the secret life of the shark. NARRATOR: Two sharks with cameras can scout a much bigger section of the giant lagoon than a couple of divers. KORI: So if we can see what they're doing and why they're doing it, I think that's really helpful for the behavior, and also to see habitat. NARRATOR: With other species like bull sharks and great whites, the young segregate themselves so they aren't attacked and eaten by the adults. Maybe that's what's happening here. PIERRICK: They come all at the same time.

NARRATOR: Pierrick Seybald is Kori's safety diver. She'll need him for this dive. She's going to try and attach the cameras to the tiger sharks...by hand. KORI: Alright, Andy, I'm going to go ahead and jump in. ♪ ♪ ♪ ♪ NARRATOR: These young tigers are more unpredictable than adults. ♪ ♪ ANDY: One coming up behind you! NARRATOR: Kori wants to start with a small juvenile. She makes her move. ♪ ♪ ♪ ♪ ♪ ♪ ANDY: Got it! NARRATOR: They still need a second volunteer. This one's a sub-adult. ♪ ♪ KORI: That one's bigger than all of

them. Want me to go? ANDY: Let's do it. ♪ ♪ ♪ ♪ ♪ ♪ NARRATOR: Kori's two for two. ANDY: Nice work! NARRATOR: But this camera shark moves in for a close up. ANDY: (muffled) Oh, oh, oh. NARRATOR: The first thing it films is a beeline right for the safety diver. ♪ ♪ Pierrick rubs receptors located in her snout. ♪ ♪ He wants to calm her down. ♪ ♪ ♪ ♪ But it's clear. This young tiger doesn't want calm. It wants a diver. PIERRICK: Oh! NARRATOR: The search for a mega tiger shark named Kamakai has

led to a vast Polynesian lagoon full of juvenile tiger sharks. One of them is after the dive team. ♪ ♪ But shark scientist Kori Garza keeps her cool. She even adjusts the fin cam on the fly. ♪ ♪ ♪ ♪ Young tigers can be very erratic. The team members decide not to push their luck. ANDY: Get on the boat. ♪ ♪ ♪ ♪ ♪ ♪ KORI: Phew! ANDY: Wicked. KORI: It was crazy, she came right up, I dropped on top of her, got it on, it was a little bit crooked, but just, a little bit

adjustment down, I think... ANDY: Yeah, but at first you had to kinda like push her off a few times. It took a little while, but I think we got it on the perfect juvenile. I think now she'll cruise off, do something sharky. We'll pick the camera up in hopefully a couple hours. Unless she eats it, but, um, I think that's a perfect shark. NARRATOR: The fin cam is designed to release after a few hours. A tiger shark can cover a lot of ground in that time. They've been known to swim 60 miles a day. The

footage should give Kori and Andy a good idea of what the young tigers are doing in the lagoon, and why there are no large older females. Three hours later, they get a signal on their receiver. (beeping) ANDY: Kori, it sounds like the camera has popped up way out there, like way outside the lagoon. But in the deep water, yeah? KORI: Yeah. NARRATOR: The first camera they detect is from the bigger tiger, the sub-adult. Looks like the camera came off as she headed out of the lagoon. ANDY: Alright! Nice work! NARRATOR: But the smaller female dropped

hers... ANDY: We got it, Kori, just off the right there. NARRATOR: ...inside the lagoon. ANDY: Nice. Two fin cams deployed, two retrieved. Let's check the footage. What is that? KORI: That's a fish. NARRATOR: The bigger shark headed out. ANDY: Looks like she's heading deeper. NARRATOR: At around eight feet long, and at least four years old, she's approaching adulthood, and heading outside the lagoon. ANDY: Cool. NARRATOR: It's more dangerous out here. The camera picks up hammerheads, big ones. ♪ ♪ Adult hammerheads are cannibals, known to eat smaller sharks, like young tigers. Kori and Andy came here

to find the giant female tiger shark, Kamakai. So far there's no sign of her. But what they have found is a lagoon full of teen tigers. ANDY: There's like one, two. This little one is obviously encountering other juveniles here. That one right there, that one right there. That's a rad shot of that tiger cruising amongst its friends. They're not being aggressive. KORI: They don't seem to be really in competition. NARRATOR: Tiger shark pups are much smaller when they're born: 20 to 30 inches long and very vulnerable. Maybe all these young sharks were born nearby and

came inside the lagoon for a reason. ANDY: If they swim out the pass, they're basically subject to being predated on by big sharks. KORI: I think this is where they kind of learn to be sharks, and once they're big enough to get past that learning curve, then it's not as dangerous for them to go out. NARRATOR: The lagoon is like a secret hangout for mega sharks in training. The strong currents in and out provide a constant supply of food. And the shallower water keeps out the larger hammerheads. ANDY: If I was a little tiger shark,

I would hang out in this lagoon, too. It's like the perfect safe zone, where there's food, safety, friends. It makes perfect sense. NARRATOR: The pieces of the puzzle are coming together. Huge females gather at Tahiti, showing mating scars. Maybe Kamakai was so big because she was pregnant. KORI: That could be one reason that she was so wide. It's very possible that she was coming in, dropping those babies off, and heading back out. NARRATOR: A lagoon full of young tiger sharks, which suggests a rare pupping ground may be nearby. Kori and Andy are finding evidence for

each stage of the tiger shark life cycle within the Polynesian sanctuary. ANDY: Look! NARRATOR: And now, for Kori, a startling new discovery. KORI: Oh, look at that. ANDY: Oh, wow. KORI: Oh, wow! ANDY: Whoa! NARRATOR: The giant female shark named Kamakai is out there, somewhere. Shark experts Andy Casagrande and Kori Garza are at a remote atoll in French Polynesia to find her. No sighting of Kamakai yet. But their fin cam footage reveals a teen tiger training ground. ANDY: Okay, one, two. KORI: Three tigers. ANDY: There's three right there, and another tiger. KORI: She's following... ANDY:

Following that tiger. KORI: Yeah, she's following that one. NARRATOR: Adult tigers like Kamakai are loners. But these young sharks appear to work together. KORI: They come in, in a fleet. ANDY: Exactly. KORI: It's like they disappear, they come in, it's like, alright, who's initiating this? 'Cause one's gotta be leading the bunch or are they opportunistic? Is it, "Okay, he's going, she's going for it, so I have to go for it, too," or is it a community thing? ANDY: Another one coming here. KORI: See, look right there. ANDY: Yep. Oh, wow. NARRATOR: Some sharks do live

and hunt in packs. Gray nurse sharks in North Carolina, lemon sharks in Brazil, and grey reefs in Fakarava Atoll have all been observed working together. But this fin cam footage is the first evidence that young tiger sharks may do the same thing. It may be an important step in becoming a giant like Kamakai. ♪ ♪ The team wants to film a coordinated group attack to prove it wasn't just a random event. ♪ ♪ ♪ ♪ The young tigers in the lagoon have already shown they can be aggressive. Kori's volunteered to be the bait. She'll have

to be careful. ANDY: Alright, Kori, this is it, 360 cam. I'm gonna basically start rolling here. Wherever the sharks are, just keep it pointed that way. It's gonna be recording 360. Any direction that sharks come from, this thing will pick it up. So the tricky part is just kinda not letting the sharks eat it. NARRATOR: The 360 camera will capture every angle. KORI: This'll be really helpful for the behavioral aspect. Are they one following the other? Are they communicating any way through body language? I think this will help us take a deeper look into what

exactly is happening. Alright, Pierrick, let's jump in. ANDY: There you go, Kori. ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ NARRATOR: Once again, young, unpredictable tigers surround them. KORI: Ka ka ka! ♪ ♪ ♪ ♪ NARRATOR: And once again, moving in unison... just like the fin cam footage. ♪ ♪ This is not a coincidence. And they come for Kori. ♪ ♪ They grow bolder. ♪ ♪ Circling upward. KORI: Ka ka ka ka. ♪ ♪ NARRATOR: Now some of the largest sub-adults join in... ♪ ♪ ♪ ♪ ...from every angle. ♪ ♪ ♪ ♪ Is it

a hunting strategy? ♪ ♪ ♪ ♪ MAN: Tiger! Tiger! NARRATOR: If it is, it works. ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ NARRATOR: A frenzy of young tiger sharks swarm shark expert Kori Garza. ♪ ♪ ♪ ♪ But she stays calm to get the shots. ♪ ♪ A dangerous move... ...but also a potential first for tiger shark research. ♪ ♪ After several minutes of being deflected, the sharks change tactics. ♪ ♪ ♪ ♪ Kori catches her breath as they seem to disappear. ♪ ♪ But this is not over yet. ♪ ♪ They regroup and

turn back as a single force. KORI: Ka ka ka ka! ♪ ♪ NARRATOR: Kori's safety diver, Pierrick, decides the risk is too high to continue. ♪ ♪ KORI: Whew! ANDY: Whoa! KORI: That was... ANDY: That was intense. KORI: That was intense. There were some pretty insane moments on that camera. ANDY: Yeah, I'm pretty sure it should have covered all the action. I pretty much lost count of the sharks. KORI: At one point all I saw was just stripes everywhere. ♪ ♪ ANDY: I saw you deflecting one coming here and another one behind you. And then

at one point you and Pierrick were literally like dancing on tigers. PIERRICK: That was crazy, huh? ANDY: You two had your hands full there with two behind you. I was filming, all looking behind me like one arm in the camera, and then down deep there were more. I hear people on the boat saying, "Tiger, tiger!" KORI: See what I mean, how they'll disappear? And then instead of just like one coming, it's boom, all at once. It's hard to handle that many sharks. ANDY: It's true, it goes quiet, like everything evaporates. And then all the sharks

just come back in force at the same time like a little army. KORI: They are a little army. NARRATOR: The 360 camera will give a full picture of what's going on. And it may hold clues as to why Kamakai was in the area and how she got so big. ANDY: Here we go, 360 tiger sharks. NARRATOR: This lagoon is full of surprises. ANDY: Wow, clearly this lagoon is loaded with tiger sharks. NARRATOR: Young tiger sharks everywhere, all potential giants in the making. And strange behavior never before seen. ANDY: This 360 shows us that all of

the sharks, en masse are showing up together and leaving together, pretty much every single time. KORI: Every single time. It's not, and this is not... ANDY: This isn't coincidence. KORI: Yeah, because it's happening every single time. NARRATOR: This may be a world first. The 360 camera footage suggests that these young tiger sharks hunt as a pack, working together to take on prey. KORI: It's better for them and easier for them to learn to cooperate rather than to spend their whole time fighting each other. 'Cause that's just one more struggle that they have to overcome to

make it to be, you know, a big mature shark. NARRATOR: It's a strategy that likely served Kamakai well in her youth, and allowed her to become a super-sized tiger shark. KORI: So clearly this population of juveniles is unprecedented. And what we've seen here has been incredible. ANDY: And even if we didn't find Kamakai, these could totally be her pups. KORI: They could. NARRATOR: The spawn of Kamakai may now hunt as a pack, and grow as giants together. KORI: I know that you came here to see Kamakai, one of the biggest sharks I have ever seen

in my life. ANDY: Maybe the biggest in the world? KORI: Maybe the biggest in the world. But I think what we found is even bigger. And what's cool is this is just the beginning. NARRATOR: 14 years after protection, the waters off French Polynesia have transformed into a big tiger paradise. It's revealing incredible new insights about tiger shark behavior... ...and providing a safe haven where a shark like Kamakai can birth, live and grow to the size of a legend. NARRATOR: In 2013, cameras captured a glimpse of what's believed to be the largest great white shark ever

recorded: Deep Blue. She was never seen again, until now. But that's just the beginning. What happened next was one of the most unbelievable shark encounters... TIM: She's coming right here. Holy (bleep)! NARRATOR: Of all time. KIMBERLY: My boat is sinking. NARRATOR: Hawaii, a tropical paradise, known for white beaches, stunning scenery and abundant marine wildlife. Many shark species call these waters home. Tiger sharks, hammerheads and oceanic white tips are common. But it's extremely rare to see a great white. But on an early morning in January, 2019, that was all about to change. REPORTER (over TV): A

whale carcass we first told you about last night as breaking news is now on the reef off Sand Island. The carcass was spotted yesterday off of Kewalo. The current carried it west and now it's stuck here on the reef off Sand Island Beach Park. DAVID: I would just professionally advise you not to swim here because there have been tiger sharks seen on the carcass today and yesterday there were as many as 15 to 20 tiger sharks on the carcass at one time. NARRATOR: On January 11th, 2019, everyone on the island of Oahu was talking about

a huge sperm whale carcass near the shore, attracting sharks. An unusual sight for most, but for wildlife photographer, Kimberly Jeffries, and boat captain and diver, Mark Mohler, it sounded like a chance to capture some amazing photos. MARK: So we heard about the whale on the news. We had reports of tiger sharks, oceanic white tips, even hammerheads. We wanted to get out as soon as we could and by the time we made it out, the whale had already washed ashore right here at Sand Island. KIMBERLY: That's exactly where it was. It was beached right there on

the sand next to the rocks. So we were kind of disappointed that we missed our chance. NARRATOR: Kimberly is a professional wildlife photographer and conservationist. Capturing amazing images, above and below the water. She and her boyfriend, Mark, dedicate as much of their time as possible to their true passion, photographing and studying animals in the water. On January 12th, the Department of Land and Natural Resources tows the dead whale back into the ocean. KIMBERLY: I was scanning the radio and I heard reports that they had dropped the whale carcass eight miles off shore. And I was

like, "Let's go check it out." NARRATOR: Excited for a second chance to see sharks feasting on the whale, the next morning, Kim, along with two other friends, Andrew Gray and boat captain, Danny Roberts, set off in search of the carcass. MARK: I had already made plans to SCUBA dive with some friends. And we basically agreed that if they found it, let me know and I'll try to get my boat out there. DANNY: So we were out looking for the whale carcass. I did see something that looked white, almost like the water breaking in the distance.

It turns out to be the carcass. ANDREW: We got about 100 meters off the whale and started gearing up. NARRATOR: This is the moment they're been waiting for. A chance to see whatever might be lurking under the water, scavenging on the giant carcass. ANDREW: And at that point, tiger sharks started swimming up to our boat and checking us out. So we knew it was gonna be a good dive. NARRATOR: Andrew and Kim get in the water next to the whale, excited to shoot. CHRIS: Tiger sharks are probably the apex predator around the Hawaiian Islands. And

they'll eat everything. But, when a dead whale shows up, it's like ringing the dinner bell for tiger sharks. So, by and large, sharks don't consider humans food. We are simply not on their menu and there's growing data sets to show that that's the case. But occasionally, people do get bitten and we don't really know why. One possibility is defense. They may actually bite people because they feel threatened. So, getting in the water around these sharks is obviously a really cool experience, and the chances of being bitten are obviously low, but we never advise that for

the public because that's a good way to become an accident. NARRATOR: But an ominous quiet surrounds Kim and Andrew. Strangely, the tiger sharks have vanished. After only minutes in the water, Kim and Andrew discover the tiger sharks had a very good reason to leave quickly. ANDREW: A big shadow started appearing, headed right towards us. And I was thinking, what in the world is this? 'Cause it was way bigger than any shark I'd expect. KIMBERLY: She was by far the biggest white shark I've ever seen and, honestly, her girth was approaching pilot whale size in just

sheer mass. ANDREW: This white shark swims right by Kim and I, and heads directly towards the whale and took a big bite. DANNY: Andrew yells, "That's a white!" you know, "That's a great white!" There it is. She is massive. I'm not gonna lie, I got chills ran up my spine and that just changed the whole ball game. ANDREW: This thing is so big. NARRATOR: As a marine biologist, Andrew calculates the size of marine animals for his job. ANDREW: I would estimate this shark at 6 meters, that's about 20 feet long. NARRATOR: This seemed like the

opportunity of a lifetime and Kim didn't want Mark to miss it. KIMBERLY: We shouted at Danny to call Mark, 'cause I wanted him to get there right away. Danny, you have to call Mark! DANNY: I was told to contact Mark. He was out diving with another group of friends. MARK: It definitely crossed my mind that Danny would have been messing around with us. He tends to be a jokester. NARRATOR: Once he gets the message, Mark jumps at the chance to see a great white, quickly heading his boat towards the whale carcass. Meanwhile, Kim and Andrew

are having the diving experience of their lives. KIMBERLY: I've been to Guadalupe and I've seen quite a few white sharks in person, and this was by far the largest that I've ever seen. It was really surreal. Her pace was not what you would imagine. She was really just very stately in her movement and manner. ANDREW: She stuck around for about half an hour, circling the whale and feeding. She was incredibly fat. I didn't think she could fit anything else inside of her. And then she dove straight down under the whale and I thought, she's gone,

this is it, Mark's not gonna get to see her. I know how rare white shark sightings are in Hawaii. CHRIS: Typically, white sharks are not seen very frequently in the Hawaiian Islands. There was shark control programs that were done in the '50s, '60s and '70s and I think they caught four total, out of thousands and thousands of sharks that were caught. So while we know white sharks come to the Hawaiian Islands, they don't come in huge numbers like we see off the coast of California and Mexico, South Africa or Australia. ANDREW: While we were waiting

for Mark, tiger sharks started moving in and feeding on the whale, so I figured the white shark was definitely gone. KIMBERLY: I was a little disappointed because I wanted to share the experience with Mark and he hadn't gotten there yet, but at the same time, to have gotten that experience was so amazing. NARRATOR: With the great white gone, and tiger sharks now returning to the carcass, Mark has missed the opportunity of a lifetime. MARK: Kim and Andrew were in the water and we saw tiger sharks and they were eating off the whale. NARRATOR: But suddenly,

the tiger sharks disappear again. And it's quiet. Too quiet. Until, out of the depths, a giant emerges and it's heading straight for Mark's boat. TIM: It's coming right here! Holy (bleep)! TIM: It's coming right here! Holy (bleep)! LAURA: Oh my god. NARRATOR: A great white shark makes a surprise return to a whale carcass floating off the coast of Oahu, arriving just after photographer, Mark Mohler, jumps in the water to join fellow divers. MARK: I was on the boat and I already had my phone out. That's when I saw the shark coming up and I got

footage of it. TIM: Whoo-hoo-hoo! Oh, baby. MARK: It was too big to comprehend. This is almost as big as the boat. NARRATOR: Meanwhile, in the water, divers Mark, Kim and Andrew, watch the great white getting closer and closer to Mark's boat. MARK: The shark came up to the prop and I thought it was gonna bite my prop on my boat. NARRATOR: But the great white shark decides rotting whale meat is a better meal and returns to the carcass. Most of the tiger sharks previously feasting on the carcass have fled the scene. ANDREW: One brave tiger

shark stuck around and continued to feed. The tiger shark didn't feed for long and after taking a bite or two, headed out. CHRIS: There is actually dining etiquette that we see in sharks. So smaller ones will get out of the way when bigger sharks show up. Bigger sharks will eat smaller sharks and of course, that can easily happen at a feast like a dead whale. NARRATOR: As the great white continues to chow down, the divers capture amazing footage. MARK: This was my first experience with white sharks. Couldn't believe what I was seeing, it was a

really special experience. ANDREW: I don't think anything can ever come close to this experience. NARRATOR: This is not only a lucky day for the divers, but a tremendous opportunity for the white shark. CHRIS: If the shark had a choice between trying to chase down a tuna or take down a whale, especially one that's already dead, that's free. Didn't have to do anything to catch it or kill it. It just gets to eat. And the number of calories it can acquire off a whale compared to a tuna, are three-fold. NARRATOR: Clearly this shark is making the

most of this lucky break, filling her immense body with as much whale meat as possible. ANDREW: This thing is so big. The girth on that shark was just incredible. It was probably as wide as my arm span. NARRATOR: With such a big belly and voracious appetite, could she be eating for two? Could she be pregnant? CHRIS: It's possible that she's been out for a year and a half. She could be carrying a womb-full of close-to-term pups and getting ready to make her migration back to coastal California or Mexico to give birth. NARRATOR: White sharks typically

have between two to ten pups, but can have up to 14 shark babies. CHRIS: The fact that you might look down and see a big, fat, rotund shark doesn't necessarily mean she's pregnant. She could just have a belly full of whale in her stomach. NARRATOR: But just how much could a white shark eat? CHRIS: It's thought that a white shark could take out over 400 pounds of whale meat in a sitting. This is when a shark has been seen feeding on this whale for 18 straight hours, where you literally watch its belly extend. And it's

been estimated that a good feeding off a whale, full of fat and blubber, could last a white shark a month. So, again, we can't use how big their Buddha belly full of whale meat is to determine whether they're pregnant or not. The only way we can tell if a white shark is pregnant for sure is either take some blood and look at sex hormones in her blood, or determine whether that shark has been along the California coast and we've been able to track her movements. NARRATOR: Finally, the white shark has eaten her fill and dives

down deep, disappearing. ANDREW: We stuck around for a while, hoping she'd come back. The tiger sharks moved in and we decided to call it a day. We were exhausted. MARK: It was an incredible day on the water. NARRATOR: But who is this giant from the deep? Kim hopes her photos will solve the mystery. KIMBERLY: There have always been stories about white sharks in the Hawaiian Islands, but there haven't been very many documented instances of them. We had ID shots and video and it was more than enough to present to at least the scientific community for

identification. It really supports all the science that's been out there and the old Hawaiian stories. NARRATOR: Proof of these stories is housed at Honolulu's Bishop Museum where there is potential evidence of great whites visiting the islands hundreds of years ago. Artifacts offer hard evidence that native Hawaiians encountered these rare giants and even caught them. KAPALIKU: There is a connection to great white sharks because in the tools that are made, it is the large tooth of a great white that is specific to a weapon or to a cutting implement and we have those in our collections

today. We have our weapons case with examples of native Hawaiian weapons, Mea Kaua. And what we see are a variety of things that are meant to poke, to prod, to hit, to smash; weapons that are made using shark teeth and specifically great white shark teeth. And this one is very special. The ring slips around a finger and it can actually be held in the hand and so it's used for striking in soft areas. NARRATOR: The museum also houses hooks, once used to catch great white sharks. KAPALIKU: We have two Makau Mano, or sometimes called Kiholo,

and these are the kinds of tools that would have been used to catch the large tigers and especially the great whites. So this is another example of the connection between Hawaiians of the past and great white sharks. NARRATOR: While great white sharks have a history of visiting Hawaii, Kim, Mark and Andrew are about to discover they've just seen perhaps the largest white shark in the world. A shark last seen off the coast of Mexico. MARK: That notch is definitely a match. I got goose bumps. NARRATOR: But there's more than one massive surprise awaiting them back

out in the water. NARRATOR: Underwater photographers, Kim, Mark and Andrew, have all come face to face with a giant white shark feeding on a dead whale off the coast of Honolulu, Hawaii. Now, they're about to make an astonishing discovery. KIMBERLY: When I got home, the first thing I did was download images and videos and I immediately reached out to my friend, George, who I've worked with in the past to identify white sharks in Guadalupe. NARRATOR: Using images stored in a database, researchers have figured out a way to identify individual sharks that have visited Guadalupe Island

in Mexico. A great white hot spot in the Pacific. Currently, 261 unique white sharks have been identified. CHRIS: So it turns out white sharks have unique markings that enable us to identify them, based on the white and gray markings along the side of their body, along their gills, along their tail and of course, over the years, they acquire unique scars. During mating they quite often bite each other. In addition, they'll compete with each other over food or sometimes the things that they eat will fight back. So those unique scars and unique markings have been used

by researchers to identify individuals. NARRATOR: When shark photographer, George Probst, gets Kim's photos, he can't believe what he sees. With the help of the Marine Conservation Science Institute, he makes a startling conclusion. KIMBERLY: He responded that we had possibly seen Deep Blue, to which I said, "You're off your rocker, George and you've seen too many white sharks at this point. Just, ah, You're crazy." NARRATOR: In 2013, off the coast of Guadalupe Island, Mexico, photographer, Michael Maier, films possibly the largest great white shark ever caught on camera. Local shark researcher, Mauricio Hoyos, names her Deep Blue.

Experts at the time estimated her to be 20 feet long and 50 years old. But the short encounter left many questions. MARK: That notch is definitely, definitely a match. So it's that Deep Blue. I got goose bumps from hearing that news. Deep Blue is probably the most famous shark in the world besides Jaws, and maybe Jaws 2. KIMBERLY: When George told me that it was Deep Blue, I was really shocked because I'd been to Guadalupe and I went in the season where you see the big females, because I wanted to see the biggest white sharks

ever. But nothing that I'd seen even compared to that legend of Deep Blue. So having the chance to see Deep Blue, so far away from Guadalupe, in Hawaii, was just absolutely flabbergasting. NARRATOR: Using photos like Kim's, scientists can now better calculate Deep Blue's size. CHRIS: One of the ways we go about measuring animals are, of course, if we can catch them, we can put a tape measure on their nose, all the way to the tip of their tail and we can come up with a really accurate measurement of that shark. Now, obviously you can't catch

all sharks so another technique that scientists use to measure sharks are having something in a frame that gives us a calibration, like a diver, for example, in a frame right next to a shark, can be used as a calibration to estimate her size. If we know how big the diver is, we can estimate how big the shark is. NARRATOR: With Kim as a reference, Deep Blue is at least 20 feet long. But what was Deep Blue doing here in Hawaii in 2019, six years after being spotted off of Guadalupe Island? Back before there was shark

tracking technology, shark biologist, Leighton Taylor had a theory. LEIGHTON: I did a lot of work in the Hawaiian Islands with sharks. I made a solid guess that white sharks probably migrated here from the West Coast. NARRATOR: Today, technology proves some white sharks do make the long journey from the main land to Hawaii. CHRIS: What other researchers have found is that adult sharks, some of which have been tagged in California, have been detected along the Hawaiian Islands. While there's not a high number of sharks that have been shown to do that, there are some. You know,

25 years ago, if you'd asked any shark biologist what kind of shark we thought a white shark was, we would have said a coastal shark. And if you'd asked how we knew that we would say, "well, in the fall months along the California coast, we'd see adults coming in along the shore to feed on elephant seals." We had no idea where they went in the winter and it wasn't until the advent of some of the technology that we use, like satellite tags, that literally changed our minds overnight of white sharks from being a coastal species,

at least in the Northeast Pacific, to being an open ocean species. Most of the sharks that have been tagged and tracked, some have been tagged on the Farallons, some have been tagged in Guadalupe. We see very little movement of those sharks between those two locations. They tend to all go out to the same place, kind of in the middle of the Pacific. Researchers coin this area, kind of half way between Hawaii and Baja, the shared off-shore foraging area. NARRATOR: Footage of great whites in Hawaii is extremely rare, but deep, submersible missions have captured something surprising

and could be a clue why few people see the great whites that make the journey here. MAN: Holy (bleep)! MAN: Huge shark. Look at this guy. CHRIS: ROV and submersible studies have sighted white sharks as deep as 1000 feet around Hawaiian Islands and they're, of course, out there doing surveys to look at what animals and organisms are around the islands. MAN 3: It is a great white. That is a great white shark. MAN 4: No way. MAN 3: That is huge. Look at that, a 12-15 foot great white. CHRIS: So it's very likely that white

sharks are present here, they're just so deep we rarely see them. And they don't have to come all the way to the surface to warm up. They can come to within 100 or 200 feet of the surface and be just as warm. So it's possible that there are more white sharks here than we ever see. They're just spending more time deeper. NARRATOR: If Deep Blue swam from Guadalupe Island to Hawaii, she would have covered over 2,400 miles; a remarkable distance. But, as Kim, Mark and Andrew were about to discover, Deep Blue wasn't alone. NARRATOR: After

learning they had filmed what's believed to be the largest great white shark in the world, feeding on a dead whale off the coast of Honolulu, Hawaii, underwater photographers, Kim, Mark and Andrew head out hoping to find the carcass again. KIMBERLY: The next morning, Mark and Andrew and I went back out, just to look for the whale again. The only issue was how much it had actually drifted over the course of the night. ANDREW: We drove for about six hours looking for it and we couldn't find it, until the end of the day. NARRATOR: With no

signs of sharks, the team decides to get in to see what's hiding below the surface. MARK: We pulled up, got in the water and wanted to see what was going on underneath. ANDREW: We also wanted to check the carcass out and see how much of the whale had been eaten since the previous day. NARRATOR: The carcass is mutilated with bite marks from the night before, but one set of teeth marks is freakier than the rest. CHRIS: Sometimes we can identify the marks on a carcass, like a dead whale, based on the bites taken from certain

species of sharks. So, for example, one of the most characteristic ones are cookie cutter shark bites, which is like somebody took an ice cream scoop with a razor on it and scooped out just half-spheres of flesh. So those are very characteristic. Other species, like white sharks, usually take pretty nice excised bites, because their teeth are uniform triangles, they have nice serrated edges and they're good at excising, like a big version of a cookie cutter bite. NARRATOR: Even with evidence of various shark bites on the carcass from the night before, after hours of waiting, there was

still no sign of any sharks. KIMBERLY: It was this white mass in the water that sort of looked like tofu. There were just chunks missing out of all of it around the entire side. NARRATOR: Could the team have missed their chance at a second encounter? CHRIS: So, the one thing that we think we know about whale carcasses and feasts for sharks is that they have an expiration date. If they're freshly dead, they'll start to float. There are carcasses that you'll see that seem to be just right and it lures sharks to them like a huge

dinner bell. But then there's a period where they actually get too nasty I think and sharks stop feeding on them. So maybe the fat is putrefying, maybe all the good fat is gone, all the good parts are gone and they lose interest. NARRATOR: After several hours and zero sharks, Kim, Mark and Andrew call it quits, counting themselves lucky for what they'd captured the day before. But back on shore, they get startling news. KIMBERLY: Later that night, some additional white shark pictures started surfacing on social media. CRAIG: There, right there, right there! KIMBERLY: A white shark

was sighted at the carcass again that evening. NARRATOR: This meant that after they had left, a great white shark had stopped by for dinner. KIMBERLY: I was really disappointed that I had possibly missed out on another sighting. NARRATOR: Had Deep Blue come back or was this a different shark? MARK: The shark looked smaller and thinner, so we consulted with our shark identification folks that we were working with with Deep Blue and they did identify that this isn't the same shark, it's a new shark. NARRATOR: This new shark, dubbed Kainani, was still a larger-than-average female at

around 17 feet, a promising sign that the whale could still attract more hungry sharks. KIMBERLY: After learning about the new sighting, it really pushed us to go out the next day. NARRATOR: The next morning, Mark has to work, so Kim, Andrew and another friend, Jeff, all head out in Kim's boat, Rubber Ducky. ANDREW: At this point we realized the whale hadn't been drifting much at all, so we headed right to the point we had from the day before and found the whale quickly. There was already a boat out there with five divers. KIMBERLY: We asked

if they'd seen anything and they said they hadn't seen anything except for tiger sharks. NARRATOR: Andrew gets in the water right away, leaving Jeff and Kim on the boat. KIMBERLY: I told Jeff I was gonna pop in the water to go to the bathroom. ANDREW: Kim is hanging off the side of her boat, taking a leak, and I see a massive white shark swimming in, directly underneath her. I poke my head above the water and say, "Hey, guys, there's a shark under your boat." KIMBERLY: And I said, "Yeah, yeah, whatever, no big deal." 'Cause they'd

only seen tiger sharks in the area until then. NARRATOR: But this isn't a tiger shark, it's a great white. A very large, great white. ANDREW: I repeated myself and said, "Hey, there's a shark under your boat." When they realized what was going on, there was a quick scramble. KIMBERLY: I pushed myself back into the boat really quickly, grabbed my mask and my camera, put my fins on and rolled back into the water. NARRATOR: Unbelievably, this is a brand new white shark, estimated to be larger than Kainani and almost as big as Deep Blue. And she's

hungry too, but this shark takes a bite out of the wrong thing. KIMBERLY: My boat is sinking. NARRATOR: On day three of their expedition around a whale carcass, off the shore of Honolulu, Hawaii, Kim and Andrew, along with their friend, Jeff, have just seen a great white shark. And this one has a big appetite. KIMBERLY: I wasn't sure whether or not it was Deep Blue or not. ANDREW: This was a really large shark that, at first, I did not think was a different individual. KIMBERLY: She was incredibly huge and just incredibly majestic and she started

feeding and swimming around. She was a little bit more inquisitive than Deep Blue which was one of the first indicators to me that something was slightly different. NARRATOR: It was indeed a brand new great white shark that had never been recorded before. A large, 18 foot female that was identified through Kim's photographs. KIMBERLY: I got to name it, as a result of taking pictures and presenting it to be identified, and so I named her Haole Girl as a tribute to the Hawaiian culture and a white visitor to our islands. It's possible that this shark has

never encountered humans before, especially when you see that she is unidentified and not in any databases. So I think she was just really curious and wanted to check us out and learn something new herself. Sharks are some of the most intelligent and inquisitive animals that I have spent time with in the ocean. They have different personalities and behaviors that are unique to each of them. NARRATOR: But Haole Girl was not alone. ANDREW: This shark was being escorted by two rough-toothed dolphins that were essentially swimming around her and it looked like they were playing with her.

KIMBERLY: It was interesting because, before they showed up, I could have sworn that I heard dolphins in the water but I was like, no, we're way too far off shore, that's not possible. ANDREW: Rough-toothed dolphins on their own are a uncommon sight here and now we have two of these animals, playing around with a white shark. KIMBERLY: To see them swim around with the white shark for so long was just an absolutely incredible experience. CHRIS: On occasion, marine mammals, seals, sea lions, dolphins, even whales, will kind of trail white sharks and one of the thoughts

is, you know, maybe by being close to another white shark, it's almost like a remora, so you're not gonna get ambushed by another white shark because you're close to this bigger one. So it could be they're also using it for cover. Or the other possibility is that they kind of harass 'em. We just don't know. But dolphins are very smart, social animals and they're communicating amongst each other, which gives them an advantage. NARRATOR: After cruising with the dolphins, something else catches Haole Girl's eye. Something far more frightening. ANDREW: This shark was especially interested in our

boat. It's possible that she thought the boat was a chunk of the whale. KIMBERLY: So, the boat we were in is Rubber Ducky. It's my boat, it's about 17 feet long. A comparable size to Haole Girl. ANDREW: It has sponsons around the side of it that are filled with air and a hard hull. This shark would repeatedly come up and nose the sponsons. It was a little bit unnerving because we knew that it wouldn't take much for her to pop this thing. NARRATOR: If she takes too big a bite, she could sink the boat. KIMBERLY:

She gave a little test nibble on the starboard side and that's when she popped one of the tubes. ANDREW: We hear air hissing out. It must have been just a couple minutes before she came back to the same area, took a nice bite and made a big gash right into it. I swim up to the hull to assess the damage and that part of the boat is completely flat. I can stick my entire arm right inside of it. At this point we were eight miles off shore. KIMBERLY: My boat is sinking. NARRATOR: After an amazing

few hours with a great white named Haole Girl. NARRATOR: Kim's boat, Rubber Ducky, has been bitten by the shark and started to deflate. MARK: 10:00 on Tuesday morning, I get a text message from Kim that says, "Shark bit the boat. We are fine, come out now!" KIMBERLY: Mark came out in about an hour. He did bring some tie-downs to strap the tube in place. MARK: So, not long after I had checked their boat out and threw some supplies on it to strap the torn pontoon up, we saw that the shark was coming in behind the

boat that I brought out and that's when I got the really cool picture from the surface of Kim in the water right in front of Haole Girl. NARRATOR: Mark captured incredible photos of Kim and the shark, really showcasing her size. ANDREW: After swimming around us for hours, she eventually took off. MARK: After that encounter with Haole Girl, that was the last time we saw a white shark out with the whale and the last that anyone did that I'm aware of. NARRATOR: The encounters might be over, but the sightings of three different great white sharks in

the same location is truly remarkable and the footage captured, invaluable to scientists. CHRIS: Finding one white shark on a whale, sure, you know, that's like being out in the desert and you stumbling along blindly and finding a food truck, right? Getting three large female white sharks on a whale, that's different, right? That means those sharks had to be close enough in the vicinity to, number one, detect the odor of that whale and then also it might mean that these sharks are traveling together. It's something we've never really been able to study or understand. LEIGHTON: The

fact that we're getting more humpbacks here, more monk seals, more white sharks is an indication of our ecosystems are coming back through the positive actions of humans, protecting these animals, realizing that we need balance. CHRIS: The white shark population has probably been reduced for over 100 years, due to loss of their favorite food and over-hunting. So now that white sharks are coming back, we don't know whether the patterns we're seeing now are the patterns that were always there or whether they're new patterns as the population grows. NARRATOR: Did the team film the world's biggest known

great white shark? Quite possibly. But they definitely encountered the three largest white sharks ever recorded in Hawaii, giving hope that an even larger shark might be hiding somewhere in the deep. ♪ I'm bigger than this ♪ ♪ We've got to live like giants. ♪ ♪ We gotta keep on climbing. ♪♪ ANDREW: It's really remarkable that this whale brought in not one, not two but three different individuals that we saw, to feed. I know how rare white shark sightings are in Hawaii and this experience was absolutely incredible. By far the best I've ever had in the

water. ♪ We've got to live like giants. ♪♪ KIMBERLY: This was one of the most amazing experiences I've ever had in my life. It's something that underwater photographers dream about their whole life. There have always been legends of white sharks in Hawaii but to actually have gotten the chance to see one and then ultimately getting ready to name one was just absolutely incredible. MARK: It's mind blowing. It was an amazing experience. It was rare, we got some incredible footage of it, we got to identify three unique white sharks in Hawaii. We got a very personal

experience. We really wanted to tell our story and really share this amazing experience and how special it was to us. ♪ We live like giants. ♪♪ CREW: Oh My God. You're in a bad spot. NEIL: I know, guys, get up. NARRATOR: The chance encounter, with a giant! Maybe the largest alive. - This is insane. CREW: That's the biggest Bull Shark I've ever seen! NARRATOR: And evidence of more super-sized bull sharks! RADIO: Two bull sharks, there's two bull sharks. NARRATOR: Lurking just beneath the surface. Close to shore. STEVE: That's a BIG shark. NARRATOR: Close to people.

(Screams) Now, a team is on the trail of a family of hungry giants. JAMES: This is military grade technology. NEIL: That is epic. NARRATOR: This is the hunt. JAMES: Big bull shark down there! NARRATOR: For the world's biggest bull shark! (Screams) Florida's East Coast is one of America's most popular destinations for beach-going vacationers. But there are also year-round residents. Just beneath the surf. Florida's warm coastal waters are a hotbed for sharks. Including one of the most dangerous, the bull. Bull sharks are the deadliest sharks in the world after great whites and tigers. Adult bulls average

around seven and a half feet long. But there is one bull shark that may be queen of them all. NEIL: The amazing thing about the wild is you never know what you're going to encounter and no two days are the same. NARRATOR: For marine biologist Dr. Neil Hammerschlag, no day stands out more than May 27, 2012. Neil and his team of researchers head out to study the health and numbers of bull sharks in South Florida. NEIL: It was a normal trip; I was out with my students doing our ongoing surveys of sharks. CREW: This is

a nice piece of Barracuda, only the freshest meats! NEIL: 75 feet of monofilament, a weight, 200 foot of line, so it takes it down to the bottom, and a float. Alright, clear! NARRATOR: The University of Miami team gives average sized bulls, like this one, the usual check-up for science. CREW: If I feel where its jaw is, it can't bite me. So, I'll stay right behind it because it's a good gripping point. NARRATOR: They keep it safe by continually pumping water through its gills so it can breathe. CREW: Are we good on everything else data wise?

Here I have a biopsy and in this one here I have a fin clip sample so I'm just labeling those. NARRATOR: The grad students take samples from one bull after another. CREW: 170! 170 FL! NARRATOR: Suddenly, all the smaller sharks disappear. CREW: Hold on, hold on. Jump off. You're in a bad spot. NEIL: I know, you guys. Get off! I need you guys to get off, let's let it get it's. All of sudden, one of the lines became very difficult to bring in and I knew we had something big on it. I had no idea

how big. NARRATOR: The whole team feels it; they are in the presence of greatness. CREW: This is insane. NARRATOR: A special shark. (inaudible) CREW: This animal was very hard to bring up here. A couple of times she just ran off. And no one could hold her. NARRATOR: The largest bull shark ever caught was seven hundred and seventy-one pounds, the scientists estimate that this one is bigger. CREW: What'd you say that fish weighs? At least 800 pounds. There's no way is weighs less than 800 pounds. Bolt cutters. Can someone take a picture of this? NARRATOR: The

typical adult bull shark is in the seven-foot range. This one, just over nine feet. NEIL: I think it's a thousand pounds. That's my personal opinion. NARRATOR: They discover she's a healthy strong female. And her extraordinary girth has her tipping the scales. CREW: 196. NARRATOR: It's time to take tissue samples for DNA and draw blood from this amazing animal. CREW: Okay got it. Fresh blood sample here. So now we have our blood sample from this huge bull shark; you can see the dark and richness of that blood. NARRATOR: To reach this size, she must be around

30 years old, no one knows for sure if they get any older. No one has seen anything like her in the United States in decades. CREW: Alright guys this is loose fish. Loose fish. Fish is not secured to the boat by any... NARRATOR: It's possible that they've got their hands on the largest living bull shark in the ocean. CREW: Okay, hold on, I'm gonna use this pump to pull her out. NARRATOR: They release her no worse for wear. NEIL: It's like those wrestlers who are all neck. It's just like... I couldn't even see its eyes,

because there was just like meat around it! NARRATOR: She disappears into the depths. But not before Neil and his team give her a name that befits her size. They call her Big Bull. NEIL: In all the years of surveying sharks including hundreds of bull sharks, I'd never seen a Bull Shark anywhere near that size. NARRATOR: The photos taken of Neil with Big Bull go viral. She captures the imagination of millions the world over. No one thought the ocean had giants like this anymore. NEIL: It was incredible that we captured one of the largest specimens ever

recorded! But it also showed us how little we actually know about bull sharks. NARRATOR: They could only guess how she got this big, the range of her territory, and whether she's given birth to more giants like her. Until now. Eight years later there's more. Big bull sharks are showing up all along Florida's coastline. Fishermen notice first. -Oh my gosh, what a monster. One hundred sixty miles from where Big Bull was first captured. FISHERMAN: That's a giant bull shark. NARRATOR: Then divers report large bulls by a shipwreck. Now scientists wonder if Big Bull has ushered in

a new wave of giant sharks. Could this big momma have spawned a new generation of behemoths? NEIL: In humans, there are traits associated with being big or size that are hereditary. They're passed down from parent to offspring. And I wouldn't be surprised if the same thing applies in sharks that are hereditary, that could be contributing to the sheer size of Big Bull. NARRATOR: It's time to find out if Big Bull is still here, and if other big sharks are her pups. NEIL: The goal of this trip is to gather more information that allows us to

understand how and why she got so big, and ultimately figure out whether there's even a bigger bull shark out there. NARRATOR: If Big Bull is still out here, and the mother of a large family, it may cause concern for beachgoers. Shark attacks in the areas just north of here have increased 37 percent in that last ten years. Bull sharks are crucial for a healthy ocean and they are near threatened, so a slew of Big Bulls would give the species hope for the future. Neil is rooting for the sharks and he is not alone. Shark conservationist

and former Royal Marine commando, James Glancy, joins the marine biologist for a chance to make history. JAMES: Florida is a really special to me because it's where I first learned to dive as a kid in the nineties and I saw my first bull shark on that trip, and that gave me my passion for sharks and the ocean. So it's incredible to be back here using the military skills that I've developed over my career to support shark science and to go out and find the world's biggest bull shark! NARRATOR: But the conditions are not ideal. JAMES:

Well the sun is out today but the swell is huge. Gonna be an interesting dive. MAN: Ripping currents, deep water, poor visibility, plus bull sharks! NARRATOR: They head to where divers have seen big bulls, near a wreck site just two miles off shore. This was a drug-smuggling ship, seized by the coast guard and sunk here twenty years ago. Now it's habitat for fish of all kinds. And for bull sharks, a seafood buffet. If Big Bull is here, she would have grown close to an inch a year and now be an incredible ten feet in length.

-Yeah, we are on the wreck right now. NARRATOR: James sets up his camera to check the size of sharks. JAMES: I've got my camera rigged up with two lasers; that's gonna help us measure the sharks. NARRATOR: Problem is, bull sharks can come in a pack. JAMES: When you get more than 5 or 6 bull sharks, they get more of a pack mentality. They are an incredible predator that understands where our sensory systems are. They know how to use stealth, how to use ambush to try and get close to you. NARRATOR: It is a bull. And

it's not alone. NARRATOR: More and more show up. (Muffled noises) Suddenly, they're surrounded. Neil and James search a shipwreck for the mega shark Big Bull, and other large bull sharks that may be her descendants. DIVER: Neil, you okay? -I'm good over here. NARRATOR: Bull sharks have a pack-like mentality and swarm around possible food. They surround the divers. (Muffled noises) DIVER: They're right behind you. Let's get some cover! NARRATOR: Neil and James nestle into the wreck for protection. DIVER: Yep, one's on your right! NARRATOR: Now to get some measurements. DIVER: Neil, I'm gonna try and laser

it. I'm going to get closer. NARRATOR: James's two lasers work like an electronic ruler to confirm the size of the bulls. If one is close to ten feet long, it could be Big Bull, possibly, the largest shark alive. DIVER: There! NARRATOR: Multiplying the six inch long distance of the lasers they estimate that this shark is young, from snout to the curve of the tail, a little over five feet 1long. But nearby. DIVER: There's a Big Bull shark over there, I'm going to try to get a laser on it. I've got it. NARRATOR: A giant, pushing

nine feet. Only inches smaller than Big Bull was in 2012. They get more measurements CREW: Awesome job. NARRATOR: But the strong current, with this many sharks, turns this dive dangerous. DIVER: Hey Neil, let's head up. JAMES: How 'bout that! Ah! NEIL: That was epic! JAMES: Loads of bull sharks. NEIL: Some nice sized bulls; not as big as Big Bull, but I feel really good about this as a good starting point to take the search to the next level. NARRATOR: They've confirmed bulls as large as those reported by local divers and fishermen. While they're not quite

the size of Big Bull, this is her territory and if Neil's theory is right, the sharks here may be her offspring. There's one way to find out. When Neil encountered Big Bull, he collected tissue for DNA analysis. NEIL: Okay got it, fresh blood sample here. NARRATOR: Now, they can use it to find her offspring. She may be the matriarch of a giant family that could include other super-sized bulls. She could have more than a hundred children and countless grandchildren, a hopeful sign for a declining species. JAMES: What's exciting to me is that that bull shark

was clearly an amazing genetic specimen. So now can we find out whether she's bred successfully and passed those genes on to other bull sharks that are in the coastal areas around Florida? NEIL: The sample from Big Bull was taken as part of larger population study. Now, I've sent that sample off to various collaborators to see what else we can learn. NARRATOR: Enter shark biologist, Dr. Toby Daly-Engle. TOBY: Hey, how are ya? How's it going? NARRATOR: DNA could tell Toby if other large sharks in Florida are Big Bull's babies. TOBY: The genetics that we're doing is

basically the same exact process that would happen if you swabbed your cheek and sent it into an ancestry database. NARRATOR: As a first step, Neil has looked more closely at Big Bull's original blood sample for clues. JAMES: From the blood samples you took when you caught Big Bull were you able to tell whether she was pregnant? NEIL: The bad news is that she was not pregnant, based on the blood work, the good news is that she had recently given birth. TOBY: Wow! JAMES: Awesome. Her offspring are potentially off the coast right now. TOBY: So she

might have grandchildren and maybe even great-grandchildren. We can do DNA fingerprinting that will give us a measurement of how closely any two sharks are related. NARRATOR: Is Big Bull populating the coast with big babies? They head back out to the shipwreck, but this time it won't be just to observe. TOBY: Our goal on this expedition is to find one of her relatives and that can tell us a lot about the life history of this shark and the entire species. NARRATOR: Finding her offspring may also reveal the size of Big Bull's range, the importance of her

role in this community and even if she's still out here. The team will go face to face with large bulls to get samples. And this time, instead of blood, it'll be easier to get skin. Shark skin is up to four inches thick in some species. Female shark skin, like Big Bull's, is thicker than male skin so it can withstand bites they receive during mating. TOBY: Studies have shown that in some species, the male tooth length corresponds to that thick skin in the female of the species. NARRATOR: They'll easily handle a pinch from a biopsy spear.

It'll be like getting an ear pierced. But that doesn't mean the sharks won't react. TOBY: There's a bunch of bull sharks on the surface. They're right here. I mean this is the chance we've been waiting for. CREW: We're getting there. TOBY: Alright so, I'm gonna stay on the surface, and you're gonna load the gun and hand it down. CREW: Yep. TOBY: Okay. NARRATOR: They won't need air tanks for this dive for one simple reason. The sharks are ready for them at the surface, too many to count. JAMES: Big one here. NARRATOR: Toby is here for

science, but the sharks are here to eat. She gets a tissue sample. But then. (Screams) The giant shark Big Bull may be the largest living bull shark in the ocean. And she may have given rise to a new generation of bulls just like her, just off the coast of Florida. Dr. Toby Daly-Engel gets a DNA sample from a shark that could be one of Big Bull's offspring. But something may want a piece of her as well. (Screams) CREW: Hold on to it! Wow, I can't believe she did that. NARRATOR: The DNA expert is unharmed. It's

a freak occurrence. A mahi-mahi impaled itself on her biopsy spear. Now they scramble back to the boat before the fish blood attracts more sharks. Crew members take some of the fish for themselves. The rest goes to the sharks. And draws more of them even closer. This mission just got a shot in the arm. It's more dangerous now, but the more samples they get, the better chance they'll have of finding Big Bull or one of her offspring. TOBY: There's a ton of sharks in there. It's the perfect opportunity to sample these animals. JAMES: Certainly some huge

bull sharks around here. NARRATOR: It's a good sign for a species that's near threatened. And one of the sharks looks big enough to be the queen herself. JAMES: There's a really huge bull shark down here, Definitely. CREW: Holy (BLEEP). JAMES: Definitely worth getting a sample. CREW: Right here. NARRATOR: They switch to scuba gear so they can stay down longer. NEIL: You've got the take all opportunities to get that sample, all hands-on deck. Whoa, tons of sharks. Finally. Down below! NARRATOR: These are all big bull sharks. But the largest is down deep. NARRATOR: They collect sample

after sample. Any one of these younger sharks could have inherited Big Bull's DNA. UNK: Watch my back. NARRATOR: Biopsies from a dozen sharks. Then, finally, the largest of them comes up from the deep. It's not quite Big Bull's size. DIVER: I'm going for that big one. NARRATOR: But a healthy female. DIVER: That was awesome. Nice job! TOBY: We've got DNA! NEIL: Just got a biopsy from a bull shark. It is wild down there right now. JAMES: Yeah, maybe 15 Big Bull sharks it's unbelievable. Excellent, that is definitely mission success. NARRATOR: Toby now has what she

needs to find out if any of them are related to Big Bull. TOBY: Ooh, nice! So we've got a little bit of skin. That's that black stuff that you can see. We can get a lot of DNA off of this. NARRATOR: Big Bull is not here, but she could have had as many as seven pups every two years for most of her life. So, she may be the mother of more than 100 bull sharks. And she may still be out here, 40 years old, more than a foot longer. And still having pups. If so, Big

Bull could be at a pupping ground right now. JAMES: Where is a good location to go and see if we can find her offspring? TOBY: Well the Indian River Lagoon is a hot spot for baby bull sharks. She could have given birth there. NARRATOR: While Toby heads to the lab to work on the samples, Neil and James head to Big Bull's possible pupping ground, the Indian River Lagoon. Big bull was first captured off Marathon. The wreck site they've searched is around three miles from Palm Beach. Now they head even farther north. And into the estuary

that is the Indian River Lagoon. That's more than two hundred miles, well within her range. All bull sharks migrate once they reach maturity. Bulls may go as far north as New York. NEIL: Even if we don't find her here in the lagoon, we should find evidence she gave birth here if we capture a small juvenile with her DNA signature. NARRATOR: Few sharks would venture into this brackish lagoon. But bull sharks are special. They have adapted to live in both saltwater and freshwater. Pregnant females like Big Bull can travel into the Indian River Lagoon to give

birth, away from other predatory sharks. It's just feet from a residential community but pregnant sharks, like Big Bull, may return here again and again every two years. Neil and James join up with marine biologist, Dr. Matt Ajemian, to see if Big Bull, or her pups are here. MATT: Under normal conditions, the Indian River Lagoon can support, a nursery habitat for these animals, or so we suspect. NARRATOR: The goal is to get more samples, but the brackish water is murky. NEIL: I mean the water is like coffee. NARRATOR: It's way too dangerous to dive. Neil and

James come prepared with some cutting-edge tech. JAMES: This Remote Operated Vehicle has a 4K underwater camera, and it's also got the Blueprint Subsea Oculus Sonar. This is military grade technology that allows us to see through really dark murky water, for up to 100 feet. And that's a game changer when you're operating in these murky water conditions in the lagoon. NEIL: It essentially, shoots out this sound wave that bounces off objects, reflects back, and is able to form an image. And what I hope with this technology, is that we will see an SSO. A Shark Shaped

Object! Can you see anything on the camera? JAMES: You cannot see anything through this water on the camera, nothing at all. NARRATOR: Only the sonar can see the abundance of potential shark food. It sees in the dark. But will it see bull shark pups? Or their big mammas? NEIL: What's that? JAMES: There we go. NEIL: There's a big shark coming in. NARRATOR: The enormous shark Big Bull may be the largest living bull shark in the ocean. She could have had more than 100 pups in her life time and she may be here in the Indian

River Lagoon, giving birth to even more. NEIL: What's that? JAMES: That is big. NEIL: Yeah, and it's moving like a shark! NARRATOR: Neil and James use a remote-controlled sub with sonar to search. NEIL: Shark shaped object confirmed. JAMES: There's a second one coming in. NEIL: Yep, yep, coming in hot. And here's a third one! JAMES: Ok that's amazing! NEIL: Ok, we've got three confirmations. JAMES: This is a good spot. NEIL: Let's set up the drumlines here. NARRATOR: A new generation of supersized bulls could be here. And this is the same method Neil used when he

first captured Big Bull in 2012. NEIL: Shark shark! Yes, shark on! Shark on, let it go, watch the wake. Hold the rope. Watch out, just want to see the size. We got a bull shark! Yes! NARRATOR: It's a pup. Around a year old. Proof that this is a birthing ground. JAMES: We've got a beautiful one-meter-long baby bull shark. I'm just keeping the water going through his gills. (inaudible) NARRATOR: Its DNA will reveal if it is one of Big Bull's. If she's still alive, Big Bull's spawn may be all over this lagoon. NEIL: Perfectly adapted for

this environment. It's an incredible specimen, you can see just amazing power. Oh my goodness, I've never seen a Bull Shark this, small! Pretty much. I mean, I work with the big ones I know it sounds kind of obvious, but it's literally a miniature version of a big one! Just perfect! It's a perfect bull shark! CREW: Well he's healthy. We're going to take a quick weight. NARRATOR: PhD student Shannon Barry, will take it from here. NEIL: So will we be able to know if Big Bull came in here and gave birth by? SHANNON: Yeah, if this

is one of her offspring, we'll be able to tell based off of the genetics. NEIL: Incredible. SHANNON: So earlier this week, I received the Big Bull sample. She was part of a larger population study, so specifics into her genetic sequencing haven't been done yet. So, I'm really excited to take a look closer at that and hopefully try to find some of her offspring. NARRATOR: No sign of Big Bull, but if one of these pups is hers it'll show that her range covers most all of Florida's southern coast. It'll also prove that she was alive as

recently as a year ago! CREW: Awesome. There he goes. You see his little tag right there, look at that beautiful. Awesome job guys! Nice one. NARRATOR: They find more and more juveniles. CREW: That was the first one. NARRATOR: These youngsters may live in this area for several years, growing strong on cat fish. CREW: What a perfect specimen. NARRATOR: It'll be about ten years before they can have pups of their own. CREW: 17.2 PCL. NARRATOR: Lab work will soon show if these sharks have Big Bull's DNA. And, there's one more lead to follow. To get to

the size of Big Bull, a shark's gotta eat, and they may have just found her favorite spot to hunt. Thirty-five miles south, outside Jupiter Inlet, a shark around the size of Big Bull has just been spotted from the air, gorging on fish. Could it be Big Bull or one of her supersized offspring? (Plane chatter) Neil's colleague Dr. Steve Kajiura studies shark movements from 500 feet above the ocean. (Plane chatter) RADIO: What kind of survey are you doing? We're counting sharks along the beach here. Oh nice. NARRATOR: But down below, it's not the crystal clear ocean

you'd expect. Dark clouds sprawl across the shallows. Look more closely, and they move. RADIO: Wow look at that bait around the pier, wow that was cool. NARRATOR: This is the mullet run, millions of bait fish, and they are under attack. RADIO: Wow, big ball of bait fish and some sharks hittin' it. NARRATOR: It's the easiest meal of the year for tarpins. And sharks. NARRATOR:There's a feeding frenzy just outside of Florida's Jupiter Inlet, the mullet run. Mega-shark Big Bull or her offspring might be feeding within it right now. Dr. Steve Kajiura watches this food-chain in action.

STEVE: When these bait fish are here in large numbers, it brings in the bigger predators like the sharks. NARRATOR: Under attack from below, the mullet scramble. Black tip sharks, and tarpins move in first. STEVE: We have a little ball of baitfish, followed by more baitfish that were bisected by another shark or tarpin on the outside. NARRATOR: Then. STEVE: Loads of sharks down there. Whoa. NARRATOR: Bull sharks move in. STEVE: That's a bigshark. What is that? NARRATOR: One of them is large, around Big Bull's size. It's not here for the bait fish, it's here to eat

the other sharks. STEVE: You might have a bunch of bait fish that are attracting little black tips. Well, then those might be bringing in the Big Bull sharks to feed on the black tips in turn. And so, you've got this whole cascade that builds up, uh, from just the presence of these little tiny fish influencing huge things like, like Big Bull. Lots of sharks, lots of sharks. Look at that. That's a BIG shark. That's not a black tip. A big bull shark. NARRATOR: Steve transmits the location to James and Neil. STEVE: Hey Neil I've got

some coordinates for you. NARRATOR: They'll need to move fast to catch the mullet run in action. This may be their best chance of finding Big Bull. Or it might prove Neil's theory that Big Bull has given birth to other Big Bull sharks. But the skies are no longer safe. STEVE: Got some clouds coming in from the northwest here. NARRATOR: It's a record year for storms. STEVE: Hey Neil, looks like you might have some weather moving in towards you right now. NARRATOR: Kajiura has no choice. He has to land. RADIO: Runaway... Kajiura RADIO: Kajiura clear to

land, runway 11307. NARRATOR: But Neil and James aren't giving up, if they can find Big Bull or her pups, it will show hope for the species. JAMES: Last night we had lightening, thunder; today we've got that on the forecast, so we want to get out as quickly as possible. NEIL: It's not looking pretty, but I think it's workable and you know, we're just, we're running out of time. So we got to get out there. (dramatic music) (dramatic music) NARRATOR: After an hour of pounding they finally reach their location. JAMES: It's been an absolute epic journey

to get out of 10 to 12 feet swells. But it's definitely worth it, we're here now. NARRATOR: It's too rough for scuba gear and laser measuring devices. They'll free dive on the outskirts of the mullet run, and try to get DNA from the largest bull sharks, maybe Big Bull. Big sharks. But here the big ones are lemon sharks. Lemons are formidable predators. They're assertive and outnumber the bulls. But nowhere near as deadly and not what Neil and James are after. Then. Bulls. Two big ones. One comes in fast. Neil has his probe in position, but

he must wait for the right moment. Bull's eye! DIVER: Nice shot! NARRATOR: One down. But they also want a sample from the second larger shark. It could even be the queen of bull sharks herself, Big Bull. (Muffled noise) But a gang of lemon sharks moves in. And one of them locks in on James. Neil and James want a biopsy from a shark down below that may be Big Bull, possibly the largest bull shark in the ocean. But a swarm of aggressive lemon sharks pins them down. One of them sees James as a target. (Muffled noise)

James deflects an attack. And covers their retreat. JAMES: I think that's enough for now. The lemons are getting way too intense. I think someone's going to get bit at some point. My camera certainly did. (Muffled noise) NEIL: We're super lucky that we got one biopsy because those bulls were staying deep and any time they came kind of close the lemons would charge. NARRATOR: It's just too dangerous. They decide to call it. But Toby has been working on the DNA they already collected. And she has results. Was Big Bull just a freakish anomaly? Or has she

given rise to a new generation of giants up and down the Florida coast? TOBY: We pretty much expected to get nothing, right, I mean finding two related sharks should be like a needle in a haystack. NEIL: Like a huge ocean haystack. TOBY: HUGE haystack, and not only did we find offspring we found three offspring of Big Bull. NEIL: Are you kidding me? JAMES: An amazing story, that's good news. -Yeah. So her offspring are potentially off the coast somewhere now. TOBY: Not potentially, they're definitely there. NARRATOR: The big question is where were they found? Is Big

Bull having pups in just one area, or spreading her DNA all over Florida? NEIL: Where were these offspring? TOBY: Well a couple of different places, so we actually got one at the shipwreck. NEIL: No kidding that's deep water, I mean those were some big sharks. TOBY: Yeah, those were not baby sharks. NARRATOR: The sharks they sampled at the wreck were around ten years old. They could even be from the litter Big Bull had just before her original capture in 2012. TOBY: Second sample came from Indian River Lagoon. NEIL: From one of the small that sharks

we sampled? That's insane. TOBY: I know. I ran these data about 100 times because I thought I had to be wrong. NARRATOR: This is the pup. Just a year old. NEIL: It's an incredible specimen. NARRATOR: And from Big Bull herself, which means it's likely Big Bull is still out there. NEIL: This blows my mind. I never expected to be able to actually identify offspring of Big Bull suggesting that she's not only alive but reproducing. Where else? TOBY: Well the third offspring was one of the big sharks that was following the mullet run. NEIL: That's amazing.

NARRATOR: Four locations off the Florida coast, from Marathon where she was captured, to the wreck site, to the mullet run area, and all the way up to the Indian River Lagoon, that's at least a 200-mile range. TOBY: The fact that we are finding her offspring in these different places shows that she represents an important biological linkage between these different habitats. NEIL: Incredible. JAMES: So given that. She's potentially had many children over her life time. TOBY: Yeah, she may have grandchildren or even great grandchildren out there somewhere. JAMES: Awesome. NARRATOR: There's no sign yet that Big

Bull's off spring are any bigger than normal. But there's a lot of them. And with any luck they'll have inherited her knack for survival. She also may still be out there. An important matriarch of an enormous family. NEIL: Encountering such a large shark, for me, is actually a sign of hope. It means that this animal was able to make it past all the threats and grow to be this size. It also means there are likely other big Bull Sharks that are still out there yet to be discovered. NARRATOR: Neil may never see Big Bull again,

but he has swum with her children. They have her DNA, and given time, one of them may also claim the title of the world's biggest bull shark! NARRATOR: The great white. The shark we're told is the deadliest. But what if it wasn't true. What if there was another shark that could be even more dangerous. NARRATOR: It may be responsible for more attacks than all other sharks combined. NARRATOR: The oceanic whitetip. And it might be expanding its range. Meet what could be the world's most dangerous shark? The coastlines of the world are ground zero for most

encounters between humans and sharks. The hunting grounds of notorious predators like the bull shark, tiger, and great white. But there's another shark, that pound for pound maybe more dangerous than all other sharks. The oceanic whitetip. You probably never heard of it, because its domain is the deep seas. But it's the shark the famed underwater explorer Jacques Cousteau called the most dangerous shark of them all. MAN: I'm in trouble, mayday, mayday, mayday. NARRATOR: When a plane crashes or boat sinks in the open sea the oceanic's often show up. Earning the name The Shipwreck Shark. By some

estimates over 1000 survivors from plane crashes and shipwrecks have been killed by the oceanic. More than the great white, bull and tiger sharks combined. One of the prime spots for the oceanic is 10 miles off the Bahamas. Research scientists Brendan Talwar and Eric Schneider, of the Cape Eleuthera Institute are here to run demonstrations to reveal why the oceanic whitetip is as formidable a predator as the great white shark. BRENDAN: This is a species that used to be referred to as the most abundant predator over a hundred pounds on earth. They're basically very inquisitive sharks. They

live in a place where food is scarce and so when they get the chance to investigate something and figure out what it is, they're usually interested in that. NARRATOR: The first demonstration they'll run to show the oceanic's skills is how they react to sound. Like most sharks, oceanic's have exceptional hearing. They don't have shoreline buffets full of seals like the great white or reefs of fish like tigers and bulls. They survive in the middle of nowhere. ERIC: The ocean is similar in a lot of ways to a desert ecosystem, but I think the connotation with

that is that there's nothing out there. There's no life, there's no nutrients. There's actually a lot out here it's just is really spread out. NARRATOR: Sharks usually respond to the sound of splashes, fish in distress. But the oceanic will often investigate new noises. ERIC: These pelagic sharks out in the open ocean, they're using a number of different senses to try to find their prey. NARRATOR: Hearing may be the oceanic's longest-range sense, better than sight or smell. The sounds of boat engines or loud crashes travel for miles out at sea. Can this be a cue that

attracts an oceanic shark? Leading them to people? To test this out Eric and Brendan will try to bait an oceanic with only the sound of a boat engine. BRENDAN: The sound wave is going to reach the shark, and they're going to pick up on it using these little things that are similar to ears. We don't see them, but they do have little holes. NARRATOR: An oceanic's ear uses vibrating miniscule hairs called stereocilia to signal the brain as sound. They can pinpoint the location of a noise in any direction. An underwater loudspeaker will broadcast the sound

of a propeller and its diesel rumble. ERIC: Alright, the speaker's in, I'm going to get kitted up with scuba gear, hop in and see if we see anything. NARRATOR: Eric will enter the water to observe if any oceanic's show up. He's joined by cinematographer, Brocq Maxey. Brocq uses an underwater coms system to relay what's happening. Brendan oversees the dive from the surface. BRENDAN: Get the speaker on and hit play. We've got the speaker down there. Brocq and Eric are swimming around. Hey, Brock, can you hear me? BRENDAN: These sharks are living in a habitat that

is devoid of any kind of structure really, it pays to be very curious and rely on things like sound to investigate potential food sources. NARRATOR: Is this an underwater dinner bell for whitetips? The team plays a dangerous waiting game. An ocean away in Hawaii, another team of researchers are on a mission to find oceanic whitetips. Marine Biologist Dr. Yannis Papathanassiou and PHD candidate Sarah Luongo want to discover how the oceanic finds food away from the fish-filled reefs. YANNIS: Oceanic whitetip sharks are actually my absolute favorite shark. To me, what I admire the most about them

is that they live in essentially the oceanic equivalent of the desert. They live in an environment where there's not much food, it's not easy to make a living. SARAH: The oceanic's are something new for me, being here in Hawaii, it's a new experience. I studied great white sharks but being here and studying this pelagic oceanic whitetip is a new experience. NARRATOR: Sarah is here to help unravel a mystery. Why do oceanic whitetips follow pods of pilot whales? They aren't feeding on the whales they seem to be doing something even more extraordinary. Oceanic's could be using

pilot whales to lead them to prey. Enlisting the whales like hunting dogs guiding them to quarry. No other shark, not the tiger, bull even the infamous great white is known to do this. YANNIS: The two explanations that make the most sense to me as to why they're following these pilot whales is related to foraging. We know that pilot whales are diving deep, and they're diving deep to catch prey. Pilot whales, they have echolocation. They're much more efficient at hunting in deep, dark waters. So potentially, could the sharks be following them, going down deep and trying

to get a free meal? NARRATOR: To gather evidence if this unique behavior is true, the team will attach a special camera tag called a CATS cam. SARAH: The goal is to swim down from behind the shark, put the clamp o the dorsal fin, nice and secure. This will give us a great point of view of what the shark is seeing in front of it. After about 24 hours, these two links here are going to corrode, only the tag is going to pop off and that is going to float up to the surface. Then using this

antenna, we can listen to this rhythmic pinging sound. So, that's going to allow us to go out and hone in on where exactly the tag is in the water so we can recover it and download the data. NARRATOR: The tag will reveal the oceanic's depth, speed, and hopefully the first ever video footage of them hunting deep with pilot whales. It will be world-class free-diver Deron Verbeek's job to attach the camera tag. He has firsthand experience with the oceanic's "most dangerous" reputation. DERON: I was out in the blue one day and had an oceanic. I started

swimming back towards the boat. As it was coming back, it came at my stomach, and I'm looking down on the top of the head, and I saw the jaw slide out right in front of my stomach, it snapped, it turned, and then started going after my thigh. When I hopped up on the boat and turned around and sat down the tips of my fins were still in the water and the shark came up and snapped at my fins. It was going to eat me if I stayed in the water. NARRATOR: The team joins Colin Cornforth

of the Cascadia Research Collective. They've been tracking pilot whales in the area. YANNIS: Okay, so at 1,500 meters, we're way off the reef. We're in oceanic whitetip habitat now. We know they like deep water. Generally, the upper 200 meters in the water column. Let's go find some pilot whales and then hopefully some sharks. NARRATOR: Back in the Bahamas researchers Brendan Talwar and Eric Schneider try to lure in an oceanic whitetip shark with sound, not bait. An underwater loudspeaker broadcasts a low rumble of a diesel engine. Eric is on alert. Since the speaker broadcasts in all

directions, the shark can come from anywhere. Brocq Maxey, the underwater cinematographer relays what happens to the surface. NARRATOR: A familiar airplane shape appears. NARRATOR: The "World's Most Dangerous Shark" might not be the tiger, bull, or great white, but the oceanic whitetip. To find out what makes the oceanic so remarkable, shark researchers Brendan Talwar, Eric Schneider and cinematographer Brocq Maxey set up an experiment. The team tries to lure in an oceanic through the low frequency sound of a boat engine. A noise not usually known to attract sharks. But the ability to key into new noises makes

the oceanic a fearsome hunter. Eric is there to observe. Brocq uses an underwater coms system to relay what happens to the surface. BRENDAN: Awesome, alright, we're going to hit play. We know that the sharks are really tuned into hearing low-frequency irregular noise. NARRATOR: Like a siren's song, the broadcast boat engine calls in the shark. This oceanic might have heard it from a mile away It was awesome. A nice big oceanic down there, there are not a lot of spots in the world where you can still reliably find them, we got lucky today obviously, but making

noise got them here pretty quick today. BRENDAN: There's still a lot to learn about sound in the marine environment and what effects humans are having on changing that soundscape, but sharks that live in the open ocean definitely need every advantage that they can get to locate prey in a place where its hard-to-find food. So sound is one way to cue in on things from a long distance away. NARRATOR: The Bahamas team has shown how oceanic's will investigate any new noises, including the sound of a boat engine and its propeller. Back in Hawaii, Dr. Yannis Papathanassiou

and PHD candidate Sarah Luongo want to attach a camera on an oceanic whitetip shark that may be using pilot whales to help them hunt. Something no other shark is known to do, not even the great white. But finding pilot whales proves to be a struggle. YANNIS: It's not that easy to see them out here especially when there's getting a little bit of swell and the light's getting low. NARRATOR: No whales, but there are reports of oceanic whitetips near an aquatic fish farm. The team uses this discovery to their advantage. YANNIS: You can often see sharks

around here. We're not going to tag any oceanic whitetips if there are any here. This is more just exploratory and just to take a look and see if there's any sharks. NARRATOR: The dive is a great test run for Deron. A chance to see how close he can get to the shark when he'll tag one with the whales. It will also be a new experience for Sara, she's dived with great whites but this will be her first-time swimming with oceanic's. SARAH: It's definitely easy to look at a shark and be intimidated by it, but when

I look at a shark, I just see a beautiful incredible predator that is just trying to make its way through life. NARRATOR: Even so, Sara knows any open water dive with sharks can be dangerous, she's aware of the warning signs of an attack. SARAH: Similar to cats, they'll arch their backs. They'll curve their pectoral fins under. Things like that you want to keep an eye out for. DERON: If you see a shark and I don't see it, I need you to do something, I need you to yell 'shark' through your snorkel as loud as you

can. And then point at it and don't take your eye off of it. COLIN: We just had an oceanic whitetip come up to our divers in the water. It seems to be showing some bit of interest with the divers right now. NARRATOR: It's clear Deron won't have to chase the sharks to put on a tag. The oceanic circles closer. Sarah's dived with great whites, but that was from the safety of a cage, out in the open water anything can happen with an oceanic. NARRATOR: The oceanic whitetip has been called "The World's Most Dangerous Shark." Divers

all over the world have felt its wrath. It could be responsible for over 1000 human fatalities more than all other sharks combined, including the great white. But little is known how this apex predator hunts prey in the open ocean, far from fish filled reefs. Biologist Dr. Yannis Papathanassiou and shark researcher Sarah Luongo are in Hawaii to discover if oceanic's use pilot whales to help them find food. Step one is an exploratory dive with a pair of oceanic's. It's researcher Sarah Luong's first-time swimming with the oceanic. SARAH: Right now, we're just observing these sharks, watching their

behavior and getting an idea of what it's going to be like in the water when we're trying to tag the sharks with the pilot whales. DERON: I'm just watching for body language of the sharks, making sure there's not aggressive activity, if they're starting to get territorial or aggravated with us. NARRATOR: The sharks realize the team isn't food and disappear into the blue. The dive was a great test for how close Deron can get. It was also a memorable first dive with oceanic's for Sarah. SARAH: It was incredible, it was awesome to see them in the

water, they are one of the most beautiful sharks I've ever seen, and it was great to be face to face. One of them was swimming with some pilot fish, which is one of my favorite things to see. NARRATOR: They've seen pilot fish, now they need to find the pilot whales and deploy a camera tag on the shark. It could provide evidence of the oceanic whitetip doing something no other shark is known to do, not even the great white, use a whale to help it find prey. But they can't just tag any oceanic, Yannis needs to

get one on a shark following a pod. SARAH: When we're out looking for the whales in the water, it can be very challenging. We're just trying to see any kind of movement on the water that could indicate that there's whales and sharks there. NARRATOR: Hours pass. The tedium outweighed only by the drudgery of the search. And then. SPEAKERS: Yeah! Nice! (Inaudible) We got whales! Yeah! Awesome. COLIN: Really hoping that we have oceanic whitetip sharks following this resident group right now. DERON: So, plan here is to find a group of animals that are fairly close together

and move up ahead of the animals. Just off to the side of them, we'll slide in, hopefully there'll be a shark trailing behind them. NARRATOR: It sounds simple, but oceanic whitetips change their behavior around pilot whales. Making them even more unpredictable. DERON: Well, the oceanic's can act a little differently when they're around structure with pilot whales. They tend to be a little more curious, they'll come in fast. NARRATOR: This more aggressive behavior was seen in 2019, in Tahiti. A group of tourists also set out to follow pilot whales, this time off the coast of Moorea.

Swimmers enjoy the serene French Polynesian seas and the whales. That's when the idyllic holiday turned into everyone's worst nightmare. An oceanic whitetip attacks. A 35-year-old woman narrowly escapes with her life. But the oceanic whitetip claims both her hands before bystanders pull her to safety. Although shark attacks are rare, the tragedy in Moorea is a grim reminder that diving with oceanic whitetips, especially those following pilot whales, is incredibly dangerous. YANNIS: Yeah, so Deron will be the one to try to get the tag on and you just always want to make sure that someone's watching his back

just in case of another shark that might be coming up behind. That's going to be my job, just to basically provide safety. SARAH: I'm excited to get in, my adrenaline's going and hopefully watch Deron get a tag out. DERON: If you see a shark, don't take your eyes off it. NARRATOR: They have the whales, the sound of their boat engine, and their own splashing, all calling cards for the oceanic whitetip. NARRATOR: The oceanic whitetip, what many consider the most dangerous shark in the world, could be using pilot whales to lead them to food. To discover

if this extraordinary behavior is true, shark experts Dr. Yannis Papathanassiou and Sarah Luongo are in Hawaii to place a special camera on an oceanic. They're joined by world champion free diver Deron Verbeek on their quest. Finally, a large pod of up to 20 whales. A perfect chance to spot an oceanic. COLIN: He's doing a surface interval. Basically, oxygen enriching his blood before he potentially will go back down diving underneath to feed on squid. NARRATOR: The pilot whales swim to over 3000 feet deep to feed. This is the aphotic or midnight zone, a world of perpetual

darkness. Most sharks that hunt at the surface, like tigers and bull sharks, never travel to this abyss. Great whites are one of the few that can hunt down here and so can the oceanic whitetip. YANNIS: Oceanic whitetips we know out here, for example, they go to 600 meters. In other places, they'll dive to 1,000 meters, and down at those depths, there's certainly no light. It's going to be complete darkness for them. They're going to be relying on other senses, and it's also really cold, even for the sharks. NARRATOR: Luckily, this whale pod is still on

the surface. The team is in the thick of it. They have the whales, but on this dive, no oceanic's. YANNIS: So, we had a nice pod of pilot whales. They came right underneath us. Unfortunately, there's no sharks, which again, you don't always see sharks with these pods. Actually, one of the things we'd like to know is what makes one pod attracted to sharks and not another. SARAH: I just got out of the water; it was incredible. There was a lot of action going on down there. We didn't see any oceanic's that decided to join this

pod. So, we're going to have to keep searching and hopefully the next pod we'll have some. YANNIS: We'll just have to come out tomorrow and hopefully find them again. NARRATOR: Off the Bahamas, shark researchers Brendan Talwar and Eric Schneider are also in search of the oceanic. They're joined by cinematographer Brocq Maxey. They want to explore what makes the oceanic whitetip shark as formidable a predator as the legendary great white. They've revealed the oceanic will investigate new noises in their environment, not just the sound of fish but even the whir of propellers, and rumble of boat

engines. But to uncrown the great white as the most dangerous, the oceanic needs more than great hearing. It's often said speed kills. And one look at a great white shark and you know what that means. Their bullet shape and short pectoral fins allow them to shoot through the water and launch attacks. An oceanic whitetip is the exact opposite. A lanky drawn-out body anchored by enormous pectoral fins. It's scientific name Carcharhinus longimanus meaning sharpened nose with long fingers perfectly captures this super shark. Those "long fingers" allow the oceanic to slow cruise huge distances. Like eagles of

the sea, they glide on the currents in search of prey. Slow and steady wins the race for the oceanic whitetip. They can swim over 30 miles a day while on a hunt. But the oceanic whitetip have been known to kick it up in gear. Brendan and Eric want to observe how fast the oceanic can get by using a troll cam. BRENDAN: Fishermen will often throw cameras like this out just to get an idea of what's attacking their baits. Plus, it's just cool footage. NARRATOR: It's dragged behind the boat. They rev up the speed and see

if the oceanic can keep up. The oceanic easily showcases its sped-up nature. At 10 miles per hour, it's just under the white shark's maximum speed. BROCQ: When it comes to their flat-out speed, we know a tuna is a fast fish, we know that that's part of their prey. NARRATOR: Tuna are one of the fastest fish. So, oceanic's can become speed demons when hungry. Conserving their energy until the fatal moment and then, they're torpedoes with teeth. Not only are the oceanic's nearly as fast as a great white, but just like their famous cousins' superpower. Oceanic whitetips

can go airborne too. NARRATOR: The oceanic whitetip, sometimes called the world's most dangerous shark has a deadly array of weapons to track and kill prey. Shark researchers Brendan Talwar, Eric Schneider and cameraman Brocq Maxey have shown how the oceanic uses speed to launch their attacks. A special troll camera highlights their incredible burst velocity. BROCQ: They're quick, they're very maneuverable, they're fast, they obviously can put on some power. NARRATOR: Oceanic whitetips could be using that power just like the great white. Everyone knows about the white shark's aerial gymnastics. The oceanic might be going airborne too. YANNIS:

So, we had one shark, for example, that accelerated from 160 meters deep, vertically, till it cleared the surface at four meters a second. So, if you imagine you're on the surface and you have a shark coming from 160 meters deep that fast, that would be on you very, very quickly. Other reasons that have been put forward for breaching is one is to get rid of parasites. There has been some idea that it may be related to signaling between sharks we can't rule anything out at this point. NARRATOR: The oceanic is competitive with the great white

in hearing, speed, leaping, and diving to extraordinary depths in search of food. But there might be one thing the oceanic does that the great white doesn't use another species to find prey. In Hawaii, the team searches for oceanic whitetips trailing a pod of pilot whales. They find the whales but no sharks. They decide on a new plan. Find a shark and place the camera tag on a solitary oceanic in the hope it connects with a nearby pod. All eyes are on Deron and his skill as a free diver. DERON: Trying to clamp a camera package

onto a dorsal fin of an oceanic, a free-swimming oceanic shark, is going to be extremely dangerous. All of a sudden, I just see this thing coming in. NARRATOR: Of course, the oceanic isn't shy. DERON: And it just kept getting bigger and bigger and bigger. NARRATOR: Deron seizes the moment. The missed tag is the least of Deron's worries. DERON: I turned around, and I looked off to the side, and another smaller one was coming in. NARRATOR: With two sharks, he's vulnerable to an attack from the other when he goes in for the tag. Yannis needs to

keep an eye on Deron's blind side. One, last, chance. Triumph! DERON: Yeah! Oh yeah! Got the tag on! NARRATOR: The team celebrates, but it's a short-lived victory. The next challenge comes the following day. They need to retrieve the camera after the clamp dissolves and floats to the surface. Sarah and Yannis' task is nearly impossible. Find a camera tag in the world's biggest ocean. NARRATOR: Shark experts Dr. Yannis Papathanassiou and Sarah Luongo, need to retrieve a special camera tag placed on what may be the world's most dangerous shark, the oceanic whitetip. The tag may reveal how

oceanic's uses pilot whales to help them find prey. But all is lost if they can't find the tag. They track it through a radio signal. YANNIS: So, we're out in open ocean, we have a tag, that's floating on the surface. If the currents take it north of the island it's going to become very difficult to recover, so we really want to get it as soon as possible. How strong is the signal? SARAH: The signal's pretty strong, the gain's about quarter of the way, I'm guessing it's a couple hundred meters in this direction. YANNIS: Okay, we

must be getting pretty close then. NARRATOR: Unfortunately, the signal only weakens, and the tag is lost at sea along with its data. But luckily a photo Deron Verbeck took provides a clue into the oceanic's behavior. Tell-tale sucker marks from a giant squid's tentacles raked along the side of an oceanic. YANNIS: We don't know, again, if they are following the pilot whales down deep and using the pilot whales to find the prey. For example, the pilot whales, again, they have echolocation. They're very efficient hunters down in the deep where it's dark. They could be finding patches

of squid, for example. So, prey down there is often going to occur in patches. So, if you get in on a patch, you might be able to get quite a few prey items within a short period of time. NARRATOR: But the oceanic might be taking its super-skills to find prey in new hunting grounds. YANNIS: The oceanic whitetip is a tropical or sub-tropical species, but something to consider is that as we face changing climates, that means that water temperatures are changing and generally getting warmer. So, you may start to see, for example, reports of oceanic whitetips

extending further north as some of those water starts to warm up. So, the distribution of these animals may start to change over the next several decades. NARRATOR: Incredibly, they've been spotted off the coast of Sweden. An oceanic even attacked a boat off of Cornwall, England. Who knows where they'll turn up in the future? What could be the world's most dangerous shark may be expanding its range. It's extraordinary abilities from surviving out in the open ocean to maybe using whales to find prey might make it the ultimate predator to be reckoned with. YANNIS: I try to

avoid terms like smart, because those are human terms. And when you interact with them, when you see them in the wild, again, you can see them looking at you. You can just sort of get this feeling that these animals are checking you out, and there's something going on behind them. NARRATOR: But what might be the most dangerous shark could also be one of the most endangered sharks. BRENDAN: Oceanic whitetips have seen dramatic population declines in the past 50-plus years on the order of 50 to 95 plus percent in different parts of the world. SARAH: The

more overfishing that occurs on that species, the greater the chances are that future generations will never be able to see an oceanic whitetip. DERON: It would be really disappointing to find out that we've lost all of the oceanic's. I mean, these are an important it's like losing a wolf in the forest. NARRATOR: It's not as well-known as the tiger, the bull or the great white but pound for pound the oceanic whitetip might be the true. Ruler of the Deep.