Original subtitles

Equipment -wise and weather -wise, you psychologically prepare yourself,

with all best intentions, you can plan an expedition for two years, and you go

there, and it just goes wrong.

Sailors were actually terrified to come to this area because it was so

dangerous, and ships did not return.

Just watch that, Al.

Up on the tow line a little bit.

Al. Damn it!

Al F.

Al F, comms check.

Tom, Jack.

He didn't hear me. He didn't acknowledge.

Humankind has explored every continent on Earth, climbed its tallest mountains,

and even journeyed into space.

Thank you, Mr. President.

But there's a vast swath of our own planet that has remained a mystery.

The deep ocean.

Stretching down over 35 ,000 feet into crushing pressures.

It's been near impossible to reach.

Until now.

New engineering breakthroughs are driving an audacious global mission to

the deepest points of all the five oceans for the first time in history.

These pioneers will push technology to the limit.

What the hell was that?

We have leaking hatch.

To open up this final frontier as never before.

Trying to, like, mentally put yourself at the bottom is just mind -blowing.

Mapping hidden landscapes.

Discovering unknown life forms.

What the F is that?

And unlocking the secrets of how life in the extreme deep ocean affects our

entire planet.

Okay, I'll get to go. Get to go.

Extreme Explorer and ex -Naval Commander Victor Vescovo is putting his life on

the line, as well as $50 million of his own money to pursue his dream.

Good boy. What little boy or little girl doesn't grow up wanting to be an

explorer? And here I am with a wonderful ship, a great crew, now the deepest

diving submersible in the world.

and I get to go play in the ocean with them and discover things that have never

been seen before. How could you not be absolutely ecstatic?

His mission is to travel to each of the five oceans, discover their deepest

point, and unlock their unexplored secrets.

He has already traveled over five miles down to the very bottom of the Atlantic

Ocean. Oh my goodness, I can see the bottom.

Now he and his team are heading for a far tougher challenge.

The Southern Ocean.

It surrounds the frozen continent of Antarctica.

These are the coldest waters on the planet, and some of the roughest seas,

making it perhaps the most dangerous of all the Earth's oceans.

Some of the old -style maps had here be dragons, and sailors were actually

terrified to come to this area because it was so dangerous, and ships did not

return. They would be destroyed.

Rising winds are already testing the crew and equipment.

Getting a little brisk out here, all right.

Lovely. Might have to take the shorts off.

You have to go to long pants, too.

Boy, you came up.

Calvin, you need more than that?

Soon, they're experiencing a full -scale snowstorm.

Yeah,

I got it. In this life, I'd rather be lucky than good.

And when it comes to weather, you definitely want to be lucky.

Victor is worried about the effects of the cold on the expedition's vital

navigation equipment.

Batteries look okay.

Yeah, these guys did well.

Very strange seeing snow on my landers.

The snowstorm has been an early warning of the treacherous weather that could

lie ahead.

To search for the ocean's deepest point, Victor and his team are heading for a

dramatic underwater chasm called the South Sandwich Trench.

Over four and a half miles deep, its waters drop below freezing and are under

huge pressure, five times the crushing power of a junkyard car compactor.

It's very rarely visited, and certainly no one has ever mapped the South

Sandwich Trench, certainly not with the kind of tools that we will have

available. So in a way, this is very exciting for the whole crew because this

true exploration.

To protect Victor from the deadly pressures at the bottom of the trench,

commissioned a remarkable prototype sub at a cost of $35 million.

Surrounding the cockpit is a sphere of 3 .5 -inch thick titanium, punctured by

wide -angle viewports made of acrylic.

It's equipped with enough oxygen tanks to give him air for up to four days.

But in the Southern Ocean, The sub will have to endure temperatures far colder

than any it's experienced before.

We'll have surface temperatures that are starting at zero or one degree rather

than where we were before where the surface temperatures were 25 or 30

Celsius. The depth, it'll be minus one. It's enough to affect our cabling, our

connectors, our batteries.

If the dive succeeds, the expedition scientists will be able to hunt for

creatures of the deep and try to solve one of the Southern Ocean's greatest

mysteries.

These waters are in fact packed with oxygen and nutrients vital to life and

the source of a global ocean current that feeds the world.

Scientists are desperate to find where this lifeblood current exits the

Ocean. The South Sandwich Trench is a prime suspect, but no one has been able

dive deep enough to confirm it. The Southern Ocean, in my opinion, is one of

most important locations of the planet.

It's the lungs of Earth.

It's vital to global ocean circulation, so we need to know more. We want to know

more.

To make their bold attempt, Victor and his team only have a short window of

time, the brief Antarctic summer, when the pack ice that locks in over 7

square miles of ocean melts and retreats.

If you look at the Southern Ocean, every winter we grow almost the equivalent of

the continental United States, and then summer melt that entire continent back.

A hundred miles away from the deepest point, the team sees the chance of a

in the weather to take the sub on an exploratory dive.

It's an opportunity for chief scientist Alan Jameson to search for new creatures

in the deep, and for Victor to put the sub through its paces in the southern

ocean's freezing water.

In the spotlight is the sub designer, John Ramsey.

Mechanically, everything's great at cold temperatures. The electrical issues

with cold circuit boards and things like that, just hoping everything's going to

be fine for the guys.

First, the team needs to launch their $35 million sub off the back of a ship

being buffeted by the volatile Southern Ocean.

The most dangerous part of any of our operations will always be launch and

recovery.

That's when you're dealing with forces that are unpredictable, and managing

is a difficult thing.

Bridge, Bridge, that's all. We're ready to launch here. A little roly -poly, but

we'll give her a shot.

Yeah, let's do this. Out on the A -frame, following the tagline slowly.

The waves are coming in behind us.

LF, be advised, it's going to get a little sloppy here for a minute.

This is where we start to rock and roll. Okay. Here we go, boys. You're going to

have to do it quick.

Seriously, we're apart.

Okay, fast on the main. Fast on the main.

We're out of time. Up on the tow line a little bit.

Up.

Just hang on. Just hang on, buddy.

Get that out on the tow line.

Whoa, whoa, whoa.

Why are we doing it?

I don't know.

I don't know why.

And have that happen right at the moment you're releasing it.

You know, that's just a sickening feeling.

I'd just be advised, looks like you may have lost your starboard camera.

Roger that. Permission to dive.

Negative, negative. We've got a key release in the tow line, Joe.

Okay, let's pick up the... Yep.

Damn it!

What happened to the tow line?

Yeah, we broke the tow line.

We'll get her, McGee.

Without its tow line, the sub is now adrift.

The team must clear the remaining lines and avoid getting freezing water inside

their protective clothing.

In the cold water of the Southern Ocean, if you go into the water, you've only

got about a minute before you're in serious trouble.

Just get ready. Get people in the water.

What am I supposed to do?

After rough seas caused the sub to collide with the back of the ship on

the sub has lost one of its external cameras.

The team can't see any other damage and decide to press ahead with the dive.

Yeah, you're clear to dive.

Clear to dive.

Pumping in.

Okay, here we go.

We're descending and we're underwater.

It's eerily quiet.

Yeah.

The green color of the water here is evidence of what makes the Southern

so vital to life around the world.

Plentiful nutrients build up here during the long, dark winters, and in the

summer feed explosions of microscopic plants called phytoplankton.

They bloom in such quantities...

that NASA has even been able to track them from space.

It was mind -blowing that on that type of scale in the Southern Ocean, the

phytoplankton were responding to the surface currents and the winds and their

distribution, and you could see that from space.

Plants depend on light, and so they live in a narrow band near the surface, the

sunlight zone.

And here they in turn support an abundance of microorganisms called

which feed a rich food chain, from penguins to killer whales.

Passing below 650 feet, the sub enters the twilight zone.

Here the light dwindles, and the ocean's microscopic plants can no longer

survive.

Yet life does thrive here, like this ice fish.

Its blood still runs because it has a natural antifreeze in its veins.

And transparent jelly -like organisms called salps that string together in

chains.

See, look how dark it is.

That's incredible, isn't it?

Surface, this is LF. Present depth, 348 meters.

Victor and Alan have been underwater for just 10 minutes, but the surface crew

have spotted evidence of a worrying fault with the sub.

It seems

that when one of the

sub's cameras was damaged on launch, it breached the oil -filled pipes that

carry electrical wires around the sub.

It's now only a matter of time before seawater gets in and shorts out a vital

part of the electrical system.

The sub's power comes from six batteries packed into detachable pods on either

side of the sphere.

They, in turn, link to junction boxes that supply the sub's components.

To protect the wires and electronics from the pressures of the deep, the

and pipes are all filled with oil.

Because oil is lighter than water, It's now escaping from the breach at the top

of the sub, letting water seep in.

If it reaches the junction box, it will knock out multiple components, leaving

Victor without full control of the sub, 2 ,000 feet below the surface.

Okay, response.

Need you to instruct the LF to abort the dive. They're going to have to abort

the dive.

There are times when you have to call it, and even if it's unpopular, you do

because you have to do it safe.

Roger that.

Aborting dive.

Repeat, aborting dive.

Why? When we lost the camera, it sheared the cable, so the oil started leaking.

Oh.

Victor must now make a controlled release of enough of the diving weight

bring the sub safely back to the surface.

Ejecting weight.

All weights jettisoned.

Ascending to surface.

Get ready to brace.

We had to abort you, man, because you would have lost your modem anyway. So at

some point, you'd have been coming up even if you didn't want to.

Repairs to the damaged sub begin.

And the team encounter another deadly hazard of the Southern Ocean.

Iceberg.

A specialist ice pilot has joined forces with the captain to navigate through

these unpredictable ship sinkers.

Nine -tenths of an iceberg is underneath the ice.

And I've seen icebergs going against the wind, which is completely not

intuitive.

To begin with, the icebergs are relatively small. But then comes a

That's the target. We're dead ahead of its time.

Is this the biggest you've ever seen? I've never seen one this big. It's

extraordinary.

It goes off into the horizon.

It disappears off into the fog, and then disappears off into the fog on the

other side.

This is massive.

How long is it, Stu?

Eight feet miles, that's what I think.

It's more than a half marathon long.

The icebergs actually pose a true danger. So when I'm coming up from the

bottom... I don't want to be going up too fast because I don't know what's

directly on top of me.

Finally, the team arrive above the South Sandwich Trench, a vast underwater

canyon that's a staggering four and a half miles deep.

Their first task is to identify on the floor of the trench the precise location

of the deepest point in the Southern Ocean.

Using one of the most powerful sonar scanning systems in the world, they

to map.

for the very first time in history, an extraordinary hidden landscape.

If this were inverted and was a mountain range, it would actually be higher than

the entire Andes mountain chain.

It's massive.

The South Sandwich Trench is a staggering 600 miles long, stretching

lower reaches of the Atlantic down into the Southern Ocean itself.

But up on the bridge, the team spot a growing threat to the deep dive.

These storms are moving a little faster than expected.

The two low -pressure systems are causing all this weather to go in like a

funnel. We can't outrun it. We point the ship into the storm, and we ride it

out.

In the freezing waters of the Southern Ocean, an approaching storm is

threatening to derail Victor's attempt to discover and dive its deepest point.

We are in the screaming 60s. You do not hang out at this latitude and not have

storms come at you.

Even if it's pretty rough weather, we're just going to tough it out so we can

get the bio samples, etc. Even if we don't dive it, it's a light to deploy

landers. The landers are underwater scientific probes packed with sensors,

cameras, and traps.

They are vital for the team's mission to explore what life could possibly exist

in the icy waters 24 ,000 feet below.

Pretty exciting. We're at the limits of this planet, basically. Ultra -cold and

high pressure is very hard to adapt to.

There are five landers on board, costing up to $200 ,000 each.

But with a storm on its way, to launch and retrieve these near one -ton

could put lives on the line.

Hope it doesn't snow more. We don't want...

Despite the conditions, two science probes are heading for the seabed.

Eight hours later.

And after a remote release, they are due back on the surface.

But now the weather is taking a dramatic turn for the worse.

The nature of what we do is notoriously dangerous in terms of equipment -wise

and weather -wise. You psychologically prepare yourself because with all best

intentions, you can plan an expedition for two years and you go there and it

just goes wrong.

Where are they?

Yeah, I got them.

Hey, do you know we have a vehicle about 800 metres away?

Oh, man.

Just watch that arm.

It just ever did one little roll.

It's scary.

You see what happened to the rope?

Looks like something chewed it.

A crucial piece of scientific equipment and any extreme life forms it may have

captured are now plummeting back to the seabed, never to be seen again.

And now comes more bad news. The crew have failed to locate the second probe.

And because the Antarctic winter is now fast approaching,

they must abandon the search and move on.

Very distressing.

If we have limited time and we've got bad weather coming, we might not get

another chance.

There is better news for the sonar team mapping the trench.

Wow, who's that?

This is a seamount that's 1 ,100 meters off the seafloor.

The seamount is an extinct underwater volcano.

Previously unknown, the team get to name it.

It's a stark reminder that we know more about the surface of the moon than the

seabed of our own planet.

It's just fantastic.

I mean, nobody knew anything about this area.

And look at all the amazing features that have been imaged by the sonar.

The new data also bolsters the theory that the South Sandwich Trench is the

of the mysterious lifeblood current which feeds the world.

When you carve trenches in the ocean, you create a funnel where water flows.

Are these trenches reservoirs relatively undisturbed, or are they dynamic

throughflows of water?

To confirm the theory, the team need to sample the deep trench itself.

And now, for the first time in history, they've accurately pinpointed the very

deepest site in the Southern Ocean.

Based on the satellite data, this one right here has always been the one that

thought was going to be the deepest, or this last one.

No one considered the third one. Now we know the deepest point in the Southern

Ocean is this yellow dot right here. Wow.

A staggering 24 ,388 feet below the surface, this is Victor's target

for a dive he's determined to take on alone.

Doing things solo, you're completely responsible for everything that happens,

and you're doing it by yourself with such intense focus.

Makes it more interesting, I guess, for me. It's more exciting.

You're completely on your own.

There are now just days left before the Antarctic summer ends and the Southern

Ocean becomes too dangerous to dive.

With rough seas forecast for tomorrow, it's now or never.

But there are major concerns for Victor's safety.

I don't want to slam into the bottom of the iceberg.

There are huge bricks of ice out there. I mean, apartment -sized blocks of ice.

The expedition team are facing a major setback in their plans to send Victor

down to the deepest point of the Southern Ocean.

iceberg that could threaten his return to the surface.

Despite the risk, they decide to press ahead.

He's going to make a very careful and deliberate return to the surface. We

to make sure that he verifies himself with cameras that the surface is clear,

just in case we have him misplaced on our chart. Frankly, I'm going to use

power to slowly go up. I'm not going to drop the freeboard to rock it up.

The team prepare to launch Victor on his historic attempt into the freezing

temperatures of the deep trench beyond any hope of rescue.

Okay, you're going to have a great dive. I know, it'll be awesome. Going to the

bottom of the ocean in a submersible is like going on a space mission in terms

of the isolation.

Coming down.

That's coming down. Thank you.

Okay, let's do this. Get them in, boys.

The cold, extreme remoteness that would play on Victor's mind because if

anything goes wrong...

You're right at the end of the most stretched rubber band in history, and

really hoping that we'll clue you back.

LF, it's pumping in.

Receiving the dive.

LF,

you are a watch. You are a watch.

Roger that. I'll try to bluster it down.

Thanks.

And down we go.

Looking outside the portal, looks like a lot of food down here.

Oh, I just saw a jellyfish.

Surface, LF, present depth.

Present depth, 4, 8, 7, life support good.

Roger that, LF. We have you loud and clear.

Wow, that was quick.

I mean, he is whistling down.

Within just minutes, Victor reaches the very deepest zones of the Southern

Ocean. The midnight zone, where no light at all can penetrate, and where

extraordinary creatures are still being discovered.

The giant sea spider, whose internal organs are carried inside its legs.

The feather star, which uses the long spines along its arms to filter out

microscopic food from the water.

And visitors from above.

deep -diving sperm whales which have the largest brains of any creature that's

ever lived on Earth.

At 13 ,000 feet, Victor enters the Abyssal Zone, home to sea pigs that

inflate up to seven pairs of legs to walk around the sea floor and

alarm jellyfish that, if attacked, emit bioluminescent flashes thought to act

like a burglar alarm.

to attract bigger predators to the scene.

You can already feel the cold coming through the bottom of the submersible.

The temperature of the salt water outside has now dipped below freezing.

Let's see if I hear something unusual.

I don't have any systems on. I'm certainly not using thrusters.

It's almost like a hum.

Does it sound like a low hum?

Coming from outside the sub. I don't think I've heard that before.

Shoot, so much background noise right now.

Seems to be coming from the submarine. I can't hear the surface.

Surface, LF, present depth 5031.

I cannot read you.

LF, comms check, comms check.

He didn't hear me. He didn't acknowledge.

What's going on with that thing?

Do you read me? Do you read me at all?

As a submarine pilot, you don't want to lose communication with the surface.

That's extremely dangerous.

Extremely dangerous.

Dada! Dada!

What the... What's going on where he can't hear us?

Loud and clear!

Loud and clear!

Crystal clear audio.

I can hear him.

It's a critical moment in the dive.

Should Victor abandon or continue into the deep?

Maybe it's the cold water or something.

3 ,000 meters from the bottom. We may just keep going.

I've come all this way.

We're going to achieve the mission here.

I'm not going to work for comms out.

As he descends further into the trench, it's not just the communication system

under attack from the freezing Antarctic waters.

The electrical supply to the external cameras has also cut out.

Well, now I'm really alone. I don't have comms with the surface. I'm in a

submersible by myself going down to the bottom of the Fibonacci.

In mission control, it's been two hours since they last made contact with the

sub.

Yeah, attention all stations. Be advised, we can hear Victor, but we

communicate with him. He cannot hear us. He's very close to the lander. Yeah,

it's over a couple of hundred meters, so he must be near the bottom.

Insulation fault. That's probably just some water residue in there.

looking good.

I should be getting there really close now.

Oh, my.

And I can see something on the bottom.

Now I'm seeing the bottom much more clearly.

I've just reached the bottom of the Southern Ocean.

Looks like a moonscape out of one of my portals.

Surface, LF, at bottom, repeat.

On the bottom.

I am at bottom.

I'm at the bottom of the Southern Ocean.

Victor is an amazing 24 ,388 feet below the surface, where no human

has ever been before.

The team have also deployed here their three remaining science probes, or

landers, baited with tempting fish carcasses.

And although Victor's external sub -cameras may have cut out, amazingly,

cameras on the landers are still working.

They now capture Victor's arrival at the bottom, his life just visible across

the sea floor.

These are the first ever images captured at the bottom of the South Sandwich

Trench. And attracted by the lander's bait, there's already a crowd of super

-strained specialists, able to endure intense cold and enormous pressure.

See, tiny, white, they're like perfectly white. They look like tadpoles.

Look at that over there.

A larger creature, a little pink on the top.

He has a little pink head.

Two big eyes.

Oh, he's definitely swimming.

He's swimming away from my blast.

It seems that Victor has identified a mycid, a type of crustacean whose bright

red color, in fact, makes it even more invisible in the pitch dark of the deep

ocean.

1 ,500 feet further up the trench slope, a second lander is capturing remarkable

images of the range of life that thrives here.

Sea lilies.

and tall tubular glass sponges.

Both snag passing microorganisms drifting past in the current.

And higher up the slope still, a third lander is capturing the first ever

footage in this trench of a truly remarkable creature.

Known as a snailfish, this is the deepest living kind of fish yet

And here are two new species filmed for the very first time.

The snailfish are not here for the bait itself, but to pick off any scavengers

the bait attracts.

Finally, the lander's auto -release mechanisms activate, and they head back

the surface.

But now comes the massive challenge of safely retrieving these $200 ,000 pieces

of equipment in heavy fees.

What have we got? I think I'll just be happy if it lands on deck.

Oh! It's the most difficult sight to catch on because of the palm.

Having lost two landers already, the pressure is on.

Charlie, we're going to have to cross the tagline.

Yeah? Oh!

Don't lose your balance. No, it's the same as the thing.

Whoa. Wait, wait, wait, wait, wait.

All right, got it.

All right, what does the bait look like?

Oh, there we go. There are absolutely thousands of them.

The team have a vital horde of specimens from 24 ,000 feet down whose chemical

secrets could set the stage for scientific breakthroughs in the future.

Hopefully, we'll discover new molecules that have to do with combination of

pressure and ultra -cold temperatures.

Those may have all kinds of applications.

In China, they've been able to use the osmolite that we discovered in deep -sea

animals to actually cure glaucoma, which is a high -pressure disease of the

human eye.

Sensors on the landers have also brought back vital information that could

confirm the root of the lifeblood current carrying nutrients from the

oceans to the rest of the world.

The data is dispatched to the British Antarctic Survey in the UK, where a team

have been tracking the current at shallower depths.

The data we've been very kindly given confirm that this is Antarctic bottom

water in there, that it is going through this trench.

The actual flow through it is...

tens of times the flow of the Amazon, millions of tons a second.

It's a breakthrough that will be vital for future scientific work.

We can measure the water's flowing through to see any change, see any

that are happening before it spreads out across the whole of the world's ocean

floor. These very deep data are going to be very valuable for a long time.

Okay, I think that's a wrap.

Surfacing weight release.

And we're heading up.

Two and a half hours after leaving the bottom, Victor is now approaching the

surface. But after his radio and cameras cut out in the cold, he has no way of

knowing if there's an iceberg in his path.

If there is, the sub could be pinned beneath the ice with no way out.

It's going to come up slow.

Hope I don't hit an iceberg.

If I hear a thump, I'm stopping quick.

Going up. Just be patient. 100 meters to go.

LF, comms check on VHF. How do you read?

Yeah, do you have a visual?

Welcome back, Victor.

Thank you, gentlemen. It's good to be back.

Xeno is inbound. Should be there any minute.

Roger that. Xeno inbound.

We had some comm issues, but we're going to talk about that after. Just glad to

have you back on the surface.

And that's rigging for recovery.

Roger that. Comes for a problem, but mission was a success.

Indeed it was. Indeed it was, sir. Great job.

Thanks, sir.

Just nice and slow. Nice and slow.

The sub may be safely back on the surface, but there's a final challenge

overcome in the volatile waters of the Southern Ocean.

Ride that thing, Steve.

Good.

Oh, that was a big wave, guys. The LF does not like... being on the surface.

It's designed to just die.

Get to the bottom, get there quickly.

And she's like a wild horse, like you can try to put a rope on it, and it just

fights you, right?

Up on the main?

Yes, Steve.

You're down on the main?

Go on, Steve. Go, go, go, go.

Go on, Steve.

Two hands, man.

Up on the main. Up on the main.

That's good. That's good, Patrick.

Good

job,

buddy.

Yep.

How you doing, Steve? You want to get off there?

I can jump in there and do this.

Steve, let's get you off.

No, he sees people.

Hang in there, buddy.

Steve, let's get you off.

To prevent the onset of hypothermia, the expedition doctor must bring Steve's

body temperature back up.

He sat him down next to the heating duct in the sub's hangar.

Finally, Steve's warm enough to be moved inside.

Good work, man. Good work.

I've lived on the topic of Capricorn my whole life.

That's close to the equator.

I don't do cold water.

Thank you, Mr.

Caldwell. Welcome back, mister.

Thank you. Good to be back.

Yeah!

Great job, team!

At last, Victor is safely back on board.

He's now the only person to have reached the deepest point of the Southern

Ocean, the second of his five deeps.

Good to be back.

Good to have you back.

Some interesting moments and feeling quite alone in the middle of the

Ocean, but we got it done. It's going to be back.

All right. It's kind of cold.

This is a very high -tech machine that we took to a very inhospitable place,

it was extraordinary.

We're doing it because we're explorers, because we want to see.

We want to push the boundaries. We want to learn things that haven't been

learned before, and we want to do it together and bring it back and share it

with other people.