BERTIE: We're looking for hammerheads,
but we've had a surprise.
-Can you see it, Hugh? -Yeah.
BERTIE: A tiger shark has turned up.
(SUSPENSEFUL MUSIC PLAYING)
Well, the first rule
is to always look behind you.
Whoa, whoa! Tiger, tiger.
Whoa! That has really fired up the sharks.
Now they are just blasting around.
My adrenaline is just pumping.
(MUSIC CONTINUES)
(MUSIC ENDS)
-(THEME MUSIC BEGINS) -You ready?
BERTIE: I'm Bertie. Filming animals is my job.
That is not a chase you see every day.
BERTIE: And I take it really seriously!
Look, I'm trying to film penguins.
-(GROWLS) -Oh, and I've missed it.
Well, that was quite close.
BERTIE: I want to tell wildlife stories
in a rapidly changing world.
That sounded like a big crack!
(GASPS)
BERTIE: These are my adventures.
(THEME MUSIC ENDS)
BERTIE: I'm traveling from my home in England
to a shark-filled paradise,
off the coast of Costa Rica.
And our next stop is about 350 miles to the west.
BERTIE: A tiny dot in the middle of the Pacific:
Cocos Island.
I'm just a little bit excited because it's a place
that I've wanted to go for a very, very long time.
It's the sharkiest place on Earth.
BERTIE: After 36 hours at sea,
we've finally made it!
(BIRDS SQUAWKING)
BERTIE: Cocos is a shark magnet,
attracting 14 different species.
The best shark spectacle here is the hammerhead.
They gather here in mega schools.
But with global shark and ray numbers in freefall -
70 percent have been wiped out in just 50 years -
Cocos is one of the last places left to find them in such numbers.
Sharks are in a race against time,
and so am I.
Because Cocos is a marine reserve, I've got just 12 days
to find a giant school of hammerheads in some of the most dangerous waters
for diving in the world.
This is gonna be tough,
but I love a challenge.
Everyone ready?
Okay. Here we go.
Right, so whenever I go somewhere new,
I like to chuck the drone up to get a lay of the land.
(DRAMATIC MUSIC PLAYING)
(BIRDS SQUAWKING)
BERTIE: Oh, that is amazing.
(BIDS SQUAWKING)
BERTIE: So Cocos is the tip of a huge underwater volcano
that erupted two million years ago.
And those cliffs there, they plummet into the dark waters,
over two miles down...
and when ferocious currents smash into these rock walls,
they force up food from the deep, making Cocos irresistible to sharks...
but a nightmare for divers.
(MUSIC ENDS)
BERTIE: Before I get underwater, I need a plan.
So this is our home for the next couple of weeks:
Sharkwater.
She's a 130-foot specialist shark research vessel
that has all of our food, equipment, and medical gear
to keep our film crew, divers, and scientists alive.
We're a long way from home, so she is our lifeline.
To help me with the mission, I've brought an epic team along.
We're here to film sharks.
BERTIE: Hugh's been making underwater films for nearly thirty years.
His job is to keep divers alive.
Lost divers. You know, people do get swept away.
The currents here are furious.
BERTIE: Cristiano's been a legendary safety diver here
for over two decades.
Never dive by yourself.
Once we're ready to go up, we all go up together.
We're on our own here.
If there's an accident, there's going to be big trouble.
So what Hugh's saying is, it's all bad news.
No, we just need to be sensible!
This is why we take grown-ups on shoots because they look after us.
(AIR WHOOSHES)
BERTIE: We've also got to make sure our equipment
is in the best working order.
Yeah, there is no room for any mistakes in these sketchy waters.
Now, we're starting with basic scuba.
It's quick to set up and I've got a special face mask,
so unfortunately there is no escaping seeing and hearing me at all times.
Ready to go.
BERTIE: Sharkwater is moored here, in this sheltered bay.
We're gonna travel to the tip of a submerged mountain,
about a mile from the mainland.
Just here.
I'm gonna call it Seamount.
It's renowned as a hammerhead hotspot.
Okay, let's see if we can find some sharkies.
(DRAMATIC MUSIC PLAYING)
(MUSIC ENDS)
You can see this current is just pumping. I'm barely kicking.
And we're just zooming along.
This current's... really got a hold of me.
I'm only going in one direction.
I am not swimming against this.
Jagged rocks, spiky sea urchins. It's an underwater minefield!
And I am getting slammed around.
If I hit this reef, it is gonna shred my wetsuit.
And I, uh... I don't wanna touch the marine life, either.
It's, uh... It's impossible to control where I'm going...
and what my camera's doing.
If that gets smashed, I'm in big trouble.
I could be swept away.
Next stop: Philippines.
BERTIE: If I come up just 50 feet from the boat,
the safety team will never spot me.
I'll be gone.
This has been a real eye-opener.
I think we're going to need a different approach.
BERTIE: For our first dive, those currents were impossible
so we're leaving the Seamount and going round
to the other side of the island.
Wow, those waterfalls are amazing.
You can see why pirates came all the way to Cocos
to stock up on fresh water
and hide their treasure.
On this side of the island there's a drop off.
It's a cliff edge which plunges nearly two miles down to the ocean floor.
Here we could get better protection from the currents.
Well, it's way calmer here at the moment.
But there's something really odd happening.
It looks like a weird desert heat haze.
It's hard to believe I'm in the same ocean.
Well, I was just thinking I can't focus the camera today,
but I've just realized fortunately it's not me, it's the thermocline.
It's happening because ocean currents are smashing into the deep sides
of Cocos,
forcing cold water up from the deep
where it hits warmer water, creating this strange shimmering effect.
It's the most extreme one I've ever seen.
And it might push the sharks up from the deep.
Oh, look, our first hammerhead!
Whoa! Oh, my!
That is just...
madness.
I've been obsessed with these guys since I was a little kid.
They are just so bizarre.
They totally look like real-life aliens.
And, man, does it look cool filming the sharks
through the thermocline, through the haze.
I can't get a really good look, though.
It's just too distorted.
Well, it looks like the thermocline might be gone.
But, the... the hammerheads have done a disappearing act, too.
They're just like ghosts.
I mean, I guess at least it's given us
a tantalizing little taste of what we might see.
So cool to be around them.
And, yeah, oh, it's not scary. It's just...
awe-inspiring.
We're going to have to keep looking.
(BIRDS SQUAWKING)
BERTIE: Two locations. Limited results.
We still have time, but so far, not a lot is working.
So we're moving sites again and carrying on the search.
Well, even this drone isn't helping;
the sharks are just too deep to see from the surface.
-(BLOWS RASPBERRY) -BERTIE: And a tickly nose,
not helpful either.
Sometimes with both hands occupied...
Thank you.
BERTIE: ...you need a little extra assistance.
(CHUCKLES) I had a fly on my nose.
(BIRDS SQUAWKING)
Hang on, we might have something here.
(WATER BLOWS)
BERTIE: Just get a better position.
That is a humpback whale.
(CHUCKLES)
There's a calf. There's a calf. It's a mum and calf.
Oh, it's so cute! It's tiny.
There's dolphins on its bow.
Female humpback whale and a calf,
dolphins on its nose.
Oh, that is amazing.
So easy to get distracted around here.
BERTIE: It's Day 5,
and we've been here nearly half our time already.
We've barely seen a hammerhead, let alone huge numbers of them.
There's another trick to finding sharks here at Cocos.
On every dive, I've kept my eye out for a special little fish
that can sometimes be a sign that sharks are nearby.
It cleans the sharks, picking off their parasites
to keep them healthy.
Find these fish, and we could find the sharks.
Let's just check out over this little ridge here.
There they are!
I can see these beautiful little yellow barber fish.
They set up above the reef a cleaning station.
The station's only a few feet in size,
and all sorts of fish are coming in
to get their parasites removed.
Look, there's a rainbow runner.
I love how... how delicate the barbers are!
Hello, are you going to clean me?
(CHUCKLES)
Whoa!
Check out these guys.
These are Galapagos sharks.
And they are chunky.
Whoa! There's four or five... six, seven. (CHUCKLES)
Hey buddy!
They are way more interested in me than getting cleaned today.
They're bold and they're curious, just checking us out.
They're just doing their thing.
Awesome animals.
Look, hammerhead!
That hammer is so identifiable.
It's incredible, finally, to get a proper look through clear water.
They're called the scalloped hammerhead. The front of their hammer isn't flat.
It's these rounded scallop shapes.
That amazing hammer shape helps spread out their senses.
It moves their eyes a little further apart,
so they can see 360 degrees right round.
These guys are just one of ten hammerhead species worldwide.
Let's just sit here and see if they come any closer.
They just keep turning away right at the last minute.
Hammerheads have got an extra sense,
a real-life superpower,
because they can sense electricity.
All sharks can do this, but hammerheads seem particularly sensitive...
because just like their other senses,
that wide head spreads out the electroreceptors.
Whenever we move a muscle, we tense an arm, or our heart beats,
it gives off an electric field that they can detect.
There's a hammerhead down on the sand down there.
And that's really good for them for detecting prey in the dark.
But it's tough for us 'cause getting close to them
is gonna be a real challenge.
Well, it seems like the hammers
have moved away from the cleaning station out there
into the blue.
Current seems doable...
Whoa! There they are.
That is just so cool!
Whoa! (CHUCKLES)
This is crazy.
These guys are called bigeye jacks.
And there's no prizes for guessing why they're called bigeye jacks.
That massive eye. That's 'cause they're nocturnal feeders.
They hunt by themselves at night for little fish.
They come together in these schools in the day
for protection from their normal predators.
The problem is it doesn't protect them against humans,
the most dangerous predator on the planet.
There are so many!
Seeing this many of them together
is like getting in a time machine
and seeing what our oceans used to be like.
Here they come!
You know, this is evidence that protected areas work.
Hammerhead!
Every time a shark's been coming in, the jacks are using its skin,
its rough skin, as a scratching post.
You know, I don't know why the sharks don't just spin around
and eat the jacks. They just run away.
Those jacks have messed up our plans this time,
but the cleaning station's definitely
a good place to hang out.
I know that the hammerheads are gonna turn up here eventually.
Although they're so sensitive,
I think we're just gonna have to be patient.
BERTIE: Over the next three days we keep diving...
but the hammers are like phantoms.
And the moment they're coming straight down the barrel
and you think you've got them, and you're like, "Yes!",
they then turn and go away and... "Ah, come on!"
BERTIE: We just don't seem to be able to crack it.
And then on Day 9,
something happens that stops our mission in its tracks.
Our producer James spots a shark with a fearsome reputation,
the type that killed someone right here, just a few years ago.
Time to get out, regroup, and come up with a new safety plan.
Well, we were just coming up from a dive and all of a sudden,
there were two very big tiger sharks, and what was weird
was that they were by that island over there,
and they were right at the surface, right up against the cliff.
So I'm just putting together the drone, and I'm going to buzz it out there,
see if we can figure out what's going on.
Tiger sharks are the most deadly shark at Cocos.
And worldwide, only the great white is more dangerous to humans.
I want to work out what they're doing so we can carry on
diving safely in this area.
Well, there is our tiger shark.
It's just cruising in that channel
between the little islet of Manuelita and the main Cocos island.
Its dorsal fin is breaking the surface. Whoa, that is amazing.
(DRAMATIC MUSIC PLAYING)
BERTIE: If they're on the surface like that,
we can get underneath them safely
and see what they're up to.
It looks pretty ominous and moody right now.
I guess I'm a little nervous about getting in the water with a tiger shark.
(BIRDS SCREECHING)
That's the noise of a little booby chick,
getting fed. Sounds pretty happy about it.
All over this cliff, there's little white fluffy balls,
little booby chicks.
And you can see now the parents, who've spent the day out at sea hunting,
are now coming back to feed them.
When they get the chance, tiger sharks are known for eating seabirds.
They'll even patrol below nest sites.
Could this be what's happening here?
BERTIE: My plan is to drop in near the base of this cliff.
I've positioned a sweep boat here to pick us up
in case the currents take us,
and an emergency evacuation boat here
if we get into trouble with the tigers.
We need to get in quickly, and get away from the surface
where the tigers might mistake us for food.
Okay. Here we go. (GRUNTS)
Surface to Bertie, surface to Bertie. Comms check.
BERTIE: Yeah, Zubin, I can hear you. Can you hear me?
Thanks, Bertie. I hear you loud and clear.
Roger that. Chat to you in a bit.
Well, the first rule of looking for tiger sharks
is to always look behind you.
They love sneaking up behind things.
So that's why I keep spinning round, checking over my shoulder.
Let's just hold here.
Must say it's a bit spooky. Whoa, whoa! Big... right here, right here.
Tiger, tiger, tiger...
Big ones can be 18 feet long.
Pretty intimidating. They are a big, powerful predator.
You know, they can grow to...
2,000 pounds.
Oh, but they are just so big.
Whoa!
Look at those stripes. That's how they get their name.
There isn't a lot that isn't on the menu of these tiger sharks.
Fish, turtles, whale carcasses.
They've even found license plates inside the bellies of these tigers.
Tiger, tiger!
These sharks must just be waiting, right at the base of the cliff
for any birds, chicks or adults,
to land on the surface and then boom.
That's not a mistake that the bird gets to make twice.
These tigers are just so smart.
That's the third one we've seen, and they're all doing the same thing.
There's two tigers just here.
BERTIE: I can see how these tigers behave.
Whenever we're in this channel,
we know we've got to stay deep, stay away from the surface,
so no tiger mistakes us for a booby.
Just as we saw on the drone, the tiger sharks are patrolling
right at the surface, right in that surf zone.
And I would not want to be one of those boobies up there.
(BIRDS SQUAWKING)
BERTIE: We've learnt to think like tiger sharks
to keep us out of danger.
And if we can think like hammerheads, we could find a giant school.
(BIRDS SQUAWKING)
BERTIE: I'm meeting a man
who's already learned to think like a hammerhead
so he can help save them.
Cocos is a protected reserve, but when they leave this safety zone,
they're getting annihilated by fishing boats.
For 15 years, scientist Randall Arauz has been tagging them
to track their movements across the Pacific.
And where they go, he wants to protect.
Randall, what's the plan?
Well, the plan is to attach one of these tags onto a shark.
So, what... this is going to go into the shark.
And then, this detaches.
So we're gonna see the shark hopefully swimming away
with the tag flopping behind.
Do you have any particular tactics for sneaking up on the sharks?
So what you have to do is, you look for the cleaning station.
And remember these hammerheads are very skittish.
So any abrupt movement and they'll get scared.
So just wait for it to come in. And once he's inside
the cleaning station, getting cleaned, that's when we take our shot.
BERTIE: Randall and his team have tagged nearly 200 hammerheads.
He tracks them using a network of receivers, like this one,
dotted all over the Eastern Tropical Pacific.
I'm filming him as he tries to add one more to his tally
And there's no time to lose.
Whoa! That shark's got a hook in its mouth!
That shows these sharks are roaming outside the protected area,
and that's when they come into contact with this fishing gear.
BERTIE: At Cocos in the last 20 years, around half the population has vanished.
Worldwide, scalloped hammerheads are critically endangered.
They are being fished out of existence.
We kill more than 100 million sharks every year to cut their fins off
and put them into soup.
And if we continue the way we're going, shark species will go extinct.
And these underwater ecosystems, they need sharks to thrive.
You know, the sharks, the top predators, they keep this whole thing in balance.
BERTIE: Seeing Randall at work, I realize his mission
could be the last chance for these hammerheads.
(BERTIE CHUCKLES)
Absolute magic.
BERTIE: Each tag is another step to help save these incredible animals.
It's vital that hammerhead highways are made no-go zones for fishing boats.
Oh, and I've got so excited, I'm about to run out of air.
So I'd better go up to the surface.
BERTIE: Randall knows what it takes to get close to hammerheads.
I can see he's controlling his breathing to keep his bubbles
and noise to a minimum.
And his movements are slow and steady.
He's made himself almost invisible so he doesn't spook
these super-sensitive sharks.
Yeah, you know, the problem with...
this scuba system is...
we can be as still and hidden in these rocks as we want, but...
but still making so many bubbles, so...
I think we might need a different plan.
BERTIE: Until now, we've used scuba, which is quick to get ready
and pretty safe, so is our "go-to" equipment.
But we've also brought these: rebreathers.
They take much longer to rig, and, if you set them up wrong,
can be really dangerous.
The upside is they don't produce bubbles.
So it looks like we're going to need to switch to these
if we want to get closer to these sharks.
You can see how everyone's gone very quiet this morning.
And that's 'cause with normal scuba gear,
if you mess up your equipment setup,
the consequences aren't that bad, whereas with rebreathers,
they are serious. So, we've got lots of checklists
to make sure we're... we're doing it right.
But just got to take it a little more seriously.
(LAUGHTER)
As I said, everyone's taking it really seriously this morning.
BERTIE: I think our best bet is to head back to the cleaning station.
-Oxygen analyzed. -Yeah.
BERTIE: Just a few final checks to run through first.
MALE VOICE: Computer, electronics. Absorbent time remaining...
SILVIO: Four hours.
Those rocks down there look like a pretty good place to hide,
so I'm gonna get down in amongst the rocks,
chill out, and see if we can get the hammerheads to come to us.
Your normal scuba diving equipment, you just don't get the time down here.
You're just getting a little snapshot.
You know, these things are tricky to set up,
but they're just so good for filming.
I can sit still down here for hours...
in stealth mode!
Everywhere I look, there's little dramas unfolding.
There's a little damselfish that has hilarious little lips.
It looks like it's got lipstick on, and it's just pecking away at the algae.
(ETHEREAL MUSIC PLAYING)
Okay, I think we could be in business.
(MUSIC CONTINUES)
BERTIE: It's time to be really, really quiet. It's coming this way.
(MUSIC CONTINUES)
Whoa! That was crazy!
These rebreathers are an absolute game changer.
BERTIE: Now I'm keeping still, with no bubbles...
the two things that have given me away before
So we're nearly invisible to them.
For the first time, I'm close enough to see how they move, how they behave.
It slowed right down, and they just roll on their side,
opening up their bellies.
It's almost like a dog asking for a little scratch.
And then all the little barber fish come rushing out the reef,
and they just start nibbling.
(MUSIC ENDS)
You see that female had a big scar just above its pectoral fin.
Well, that's from mating.
The males will come along, and when they're mating
they'll bite their pectoral fin.
And this is a great sign.
It's thought that hammerheads come together in these schools
to find a mate.
Those scars right there are a clue that huge gatherings
are probably here.
I just haven't seen them yet.
They're out there in the gloom somewhere.
And we've only got one more day of diving to nail this.
(DRAMATIC MUSIC PLAYING)
Got to be able to see the sharks.
BERTIE: It's our final day at Cocos.
Our last chance to try and see if these giant schools still exist.
(MUSIC ENDS)
BERTIE: But as usual, Cocos is not gonna make it easy.
Whoa, look up there!
There's a huge school of skipjack tuna just ripping overhead.
It's like watching a big flock of birds blasting over.
And that has really fired up the sharks.
(TENSE MUSIC PLAYING)
They were just gliding around before, but now they are just blasting around.
My adrenaline is just pumping!
I wonder if they're putting the hammerheads off.
(MUSIC ENDS)
Come on. Patience.
Just let it all calm down.
(ETHEREAL MUSIC PLAYING)
Oh my...
That is just so epic!
There's too many to count, and they're just swirling 'round.
These giant schools do still exist.
This is what makes Cocos Island special.
There are not many places left on the planet
where you can see this number of sharks together.
But I wanna get in amongst that school to see what's going on.
(MUSIC CONTINUES)
The current's starting to build now.
Right. Here we go.
To infinity and beyond!
(MUSIC CONTINUES)
They're letting me in amongst them!
And now I can see it's just a big, swirling dancefloor.
On the outside, you can see males, the smaller males, darting in,
trying to entice the big females away to mate.
This right here is the start of the next generation.
I've imagined this view in my head for years,
but I did not think we'd actually get to see it in real life.
BERTIE: It's the completion of a lifelong ambition.
But if we don't stop fishing them and protect them
once they leave the safe waters of Cocos,
these ghosts of the ocean will disappear...
forever.
(MUSIC ENDS)
(THEME MUSIC PLAYING)
BERTIE: We know where sharks migrate near Cocos,
and we know they're targeted
by fishing fleets when they leave protected zones.
Good news is that those zones are about to get bigger,
but it might come too late for the shark Randall tagged in this film.
Since October 2020, the shark moved around Cocos,
but in December, the signal went dead.
(THEME MUSIC ENDS)