[Alan] 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.
[Victor] Sailors were actually terrified
to come to this area
because it was so dangerous.
And ships did not return.
[Alan] Just watch that arm.
[Kelvin] Up on the towline a little bit!
[bleep] it!
Oh [bleep]
[Patrick] LF.
LF. Comms check. Comms check.
He didn't hear me. He didn't acknowledge.
[dramatic music playing]
[Demetri] Humankind has explored
every continent on Earth.
Climbed its tallest mountains.
And even journeyed into space.
[man] Thank you, Mr. President.
[Demetri] But there's a vast swathe of our own planet
that has remained a mystery.
[dramatic music playing]
[Demetri] 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 dive 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 a leaking hatch.
[Demetri] ...to open up this final frontier
as never before.
[Casie] Trying to mentally put yourself at the bottom
is just mind-blowing.
[Demetri] Mapping hidden landscapes,
discovering unknown lifeforms.
[Alan] What on Earth is that?
And unlocking the secrets of how life
in the extreme deep ocean
affects our entire planet.
[dramatic music playing]
[Stuart] Okay, Alan, good to go.
[Alan D] Good to go.
[Demetri] Extreme explorer and ex-naval commander
Victor Vescovo
is putting his life on the line,
as well as 50 million dollars
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,
it's now the deepest diving submersible in the world
and I get to play in the ocean with it
and discover things that have never been seen before.
How could you not be absolutely ecstatic?
[Demetri] His mission is to travel to each
of the five oceans, discover their deepest point
and unlock their unexplored secrets.
He has already travelled over five miles down
to the very bottom of the Atlantic Ocean.
[Victor] Oh, my goodness. I can see the bottom.
[Demetri] 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.
[Victor] 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.
[suspenseful music playing]
[Demetri] Rising winds are already testing
the crew and equipment.
Getting a little brisk out here, all right.
It's lovely. Might have to take the shorts off.
[laughs] Will have to go to long pants soon.
[man] Boy, it came up [bleep] quick, huh?
[Patrick] Kelvin, you need more straps?
[suspenseful music playing]
[Demetri] Soon, they're experiencing
a full-scale snowstorm.
[Patrick] [bleep] me.
[Stuart] It should be dead ahead somewhere.
I'll just lower the starboard a little bit.
Yeah, I got it.
[Victor] In this life, I'd rather be lucky than good.
And when it comes to weather,
you definitely want to be lucky.
[Demetri] Victor is worried about the effects of the cold
on the expedition's vital navigation equipment.
Batteries look okay.
Modems.
Yeah, these guys did well.
Very strange seeing snow on my landers.
[Demetri] The snowstorm has been an early warning
of the treacherous weather that could lie ahead.
[indistinct radio chatter]
[Demetri] To search for the ocean's deepest point,
Victor and his team are heading for a dramatic
underwater chasm called the South Sandwich Trench.
[Demetri] 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.
[Victor] It's very rarely visited.
And certainly no-one has ever mapped
the South Sandwich Trench.
Certainly not with the kind of tools
we will have available. So in a way,
This is very exciting for the whole crew
because this is true exploration.
[Demetri] To protect Victor from
the deadly pressures at the bottom of the trench,
he has commissioned a remarkable prototype sub
at a cost of 35 million dollars.
Surrounding the cockpit is a sphere
of 3.5-inch thick titanium
punctured by wide-angled view ports 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.
[Patrick] 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 degrees Celsius.
At depth, it'll be minus one.
It's enough to affect our cabling,
our connectors, our batteries.
[Demetri] If the dive succeeds,
the expedition scientists
will be able to hunt for unknown creatures
of the deep...
[man] Prepare lights on SCAFF.
[Demetri] ...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 are the source of a global ocean current
that feeds the world.
Scientists are desperate to find
where this lifeblood current
exits the Southern Ocean.
The South Sandwich Trench is a prime suspect.
But no-one has been able to dive
deep enough to confirm it.
[Oscar] The Southern Ocean, in my opinion,
is one of the most important locations on the planet.
It's the lungs of Earth.
[Katherine] It's vital to global ocean circulation.
So we need to know more. We want to know more.
[Demetri] 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 seven million square miles
of ocean,
melts and retreats.
[ice crashes]
[Oscar] If you look at the Southern Ocean,
every winter we grow
almost the equivalent of the Continental United States.
And in summer, melt that entire continent back.
[Demetri] 100 miles away from the deepest point,
the team sees the chance of a break in the weather
to take the sub on an exploratory dive.
It's an opportunity for Chief Scientist Alan Jamieson
to search for new creatures of the deep
and for Victor to put the sub through its paces
in the Southern Ocean's freezing waters.
In the spotlight is the sub's designer,
John Ramsay.
[John] Mechanically, everything is great
at cold temperatures.
It's the electrical issues
with cold circuit boards and things like that.
Just hoping everything's gonna be fine for the guys.
[Demetri] First, the team needs to launch
their 35-million-dollar sub
off the back of a ship being buffeted by the volatile
Southern Ocean.
[Patrick] 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 that is a difficult thing.
[John] Bridge, Bridge SO. We're ready to launch here.
We're roly-poly, but we'll give it a shot.
Okay. Let's do this. Out on the A-frame.
Follow the tagline slowly.
The waves are coming in behind us.
LF, be advised, it's gonna get a little sloppy here
for a minute.
This is where we start to rock 'n' roll.
Here we go, boys.
You're gonna have to go quick. This is the worst part.
[man] Back on the main! Back on the main!
[man] We're out of time.
[man] Up on the towline a little bit!
[bleeping]
[bleep] me.
Just hang on. Hang on, buddy.
Get that out on the tow line! Whoa, whoa, whoa!
[bleeping]
[man] Why are we doing this?
[bleep]
[man] Out on the tow line.
[Patrick] To have that happen right at the moment
you're releasing it.
You know, that's a sickening feeling.
[Victor] Status, please?
[man] Just be advised, uh,
looks like you may have lost your starboard camera.
[Victor] Roger that. Permission to dive.
[man] Negative, negative.
We gotta release the towline still.
- Okay, let's pick up the... - Yep.
[bleep]
[Victor] What happened to the towline?
We broke the towline.
[man] We'll get her, Ricky.
[Demetri] 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.
[Glenn] 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.
Let's get ready in case he falls in the water.
What am I supposed to do?
[bleep]
[Demetri] After rough seas
caused the sub to collide
with the back of the ship on launch,
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.
- [man] LF, this is SO. - [Victor] LF, go ahead.
[man] Okay, you're clear to dive.
Clear to dive.
Pumping in. Okay, here we go.
We're descending. We're underwater.
- It's eerily quiet. - Yeah.
[Demetri] The green color of the water here
is evidence of what makes the Southern Ocean
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.
[Paula] 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.
[Demetri] 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 krill
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 long chains.
[Victor] See, look how dark it is.
[Alan] That's incredible, isn't it?
Surface, this is LF. Present depth, 348 meters.
[Demetri] Victor and Alan have been underwater
for just ten minutes,
but the surface crew have spotted evidence
of a worrying fault with the sub.
[Alan] I think it's best to report, just in case.
- Kelvin, Xeno. - [Kelvin] Go ahead.
[Alan] Yeah, just for you information
Looks like I can see a small oil slick.
[Demetri] 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 boxes 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.
[Patrick] Okay, response. Need you to instruct
the LF to abort the dive.
They're gonna have to abort the dive.
There are times when you have to call it,
and even if it's unpopular, you do it because
you have to do what's safe.
[Response] LF, LF, this is the response.
Please abort the dive.
Abort the dive.
Roger that. Aborting dive.
- Repeat. Aborting dive. - Why?
[Victor] When we lost the camera,
it sheared the cable
- so oil started leaking. - Oh.
[Demetri] Victor must now make a controlled release
of enough diving weights to bring the sub safely
back to the surface.
[Victor] Ejecting weights.
All weights jettisoned. Ascending to surface.
Get ready to brace.
[Patrick] We had to abort you, man.
Cause you would have... you would have lost your...
and you would have lost your modem anyway.
So, at some point, you'd have been coming up
even if you didn't want to.
[Demetri] Repairs to the damaged sub begin.
Try to give it a little bit.
[Demetri] And the team encounter
another deadly hazard
of the Southern Ocean.
Icebergs.
A specialist ice pilot has joined forces
with the captain to navigate
through these unpredictable ship sinkers.
[Berndt] Nine tenths of an iceberg
is underneath the ice.
And I've seen icebergs going against the wind
which is completely not intuitive.
[Demetri] To begin with, the icebergs
are relatively small.
But then comes a monster.
[Stuart] That's the target. It's dead ahead of us now.
[Victor] Is this the biggest you've ever...
I've never seen one this big.
It's extraordinary. It goes off into the horizon.
[Heather] And it disappears off into the fog.
And then disappears off into the fog on the other side.
[Victor] This is massive! How long is it, Stu?
About 18 miles, this one, I think.
It's more than a half marathon long.
You know 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.
[Demetri] Finally, the team arrive
above the South Sandwich Trench,
a vast underwater canyon
that's a staggering 4.5 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 begin to map, for the very first time in history,
an extraordinary hidden landscape.
[Victor] If this were inverted and was a mountain range,
it would actually be higher
than the entire Andes mountain chain.
It's massive.
[Demetri] The South Sandwich Trench
is a staggering 600 miles long,
stretching from the 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.
[Victor] These storms are moving faster than expected.
The two low-pressure systems are causing
all this weather to go in a funnel.
We can't outrun it. We point the ship
into the storm and we ride it out.
[Demetri] 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 rough weather, we're gonna tough it out,
so we can get the bio samples,
even if we don't dive it.
I would like to deploy the landers.
[Demetri] 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.
[Paul] Pretty exciting. I mean, we are
at the limits of this planet.
Basically, ultra-cold and high pressure
is very hard to adapt to.
[Demetri] There are five landers on board,
costing up to $200,000 each.
But with the storm on its way, to launch and retrieve
these near one-ton monsters could put lives on the line.
[Alan] Hope it doesn't storm more. We don't want
ice forming on the deck.
If any one of us fell in the water,
I mean because it's so cold down here,
you get hypothermia pretty fast.
[Heather] Watch out.
[Alan D] Come down the wire.
[Alan J] It's going that way.
Okay, tags off.
[Heather] Lovely job.
[Demetri] 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.
[Alan] 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.
[man] Where are they?
[Stuart] I've got it. Okay Xeno,
we have a visual about 800 meters west of us.
[man] Roger that.
[Victor] Oh, man.
[Alan] Just watch that arm, it's just...
if it takes one little roll...
[Victor] It's scary.
[Alan D] Line come down, right.
[man] Going up!
[Alan D] Down, down, down, Down on the wire.
[man yelling]
[Paul] Where is it?
It hasn't worked, no.
[man] We have lost it.
See what happened to the rope?
Looks like something chewed it,
[Demetri] A crucial piece of scientific equipment
and any extreme lifeforms 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.
[Alan] We should be seeing that strobe
clear as day by now, right?
[Demetri] And because the Antarctic winter
is now fast approaching,
they must abandon the search and move on.
[Paul] Very distressing, yeah we have limited time
and we've got bad weather coming
and we might not get another chance
[Demetri] There is better news for the sonar team
mapping the trench.
Wow. what is that?
[Cassie] This is a sea mound that's 1100 meters
off the sea floor.
[Demetri] The sea mound 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.
[Demetri] The new data also bolsters the theory
that the South Sandwich Trench is the root
of the mysterious lifeblood current
which feeds the world.
[Oscar] When you carve trenches in the ocean,
you create a funnel where water flows.
Are these trenches reservoirs relatively undisturbed?
Or are they dynamic through-flows of water?
[Demetri] 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.
[Cassie] Based on the satellite data,
this one right here has always been the one
that we thought was going to be the deepest,
or this last one.
No one considered a third one.
Now we know the deepest point in the Southern Ocean
is this yellow dot right here.
[Victor] Wow.
[Demetri] A staggering 24,388 feet below the surface.
This is Victor's target for a dive
he's determined to take on alone.
[Victor] Doing things solo,
you're completely responsible for everything that happens.
And you're doing it by yourself
with such intense focus.
It makes it more interesting. I guess for me.
It's more exciting. You're completely on your own.
[Demetri] 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 wanna slam into the bottom of an iceberg.
There are huge bricks of ice out there.
Apartment-sized blocks of ice.
[Demetri] The expedition team are facing a major setback
in their plans to send Victor down
to the deepest point of the Southern Ocean.
Icebergs that could threaten his return to the surface.
Despite the risks, they decide to press ahead.
He's gonna make a very careful and deliberate
return to the surface.
We want 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 gonna use light power to slowly go up.
I'm not gonna drop the freeboard to rocket up.
[Demetri] 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.
[Glenn] Going to the bottom of the ocean in a submersible
is like going on a space mission
in terms of the isolation.
- [Kelvin] Coming down! - Hatch coming down. Thank you.
Okay, let's do this.
Get him in, boys.
[Glenn] The cold, extreme remoteness
will 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 you're really hoping that we'll pull you back.
[Victor] LF, It's pumping in.
Proceeding to dive.
[indistinct radio chatter]
Roger that, I'll try thrusters 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.
[man] Present depth, 487.
- Light support good. - Roger that, LF.
We have you loud and clear. Well, that was quick.
Whoo! [laughs]
I mean he is whistling down!
[Demetri] 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.
Can already feel the cold coming through the bottom
of the submersible.
[Demetri] The temperature of the saltwater outside
has now dipped below freezing.
I'm checking to see if I hear something unusual.
I don't have any systems on. I'm not using thrusters.
It's almost like a hum.
It does sound like a low hum
coming from outside the sub.
I don't think I've heard that before.
There's so much background noise right now.
Seems to be coming from the submarine,
you can't hear the surface.
Surface, LF.
Present depth, five-zero-three-one.
I cannot read you.
- I cannot read you. - LF,
comms check. Comms check.
He didn't hear me. He didn't acknowledge.
[bleep] what's going on with that thing?
Do you read me? Do you read me at all?
[Kelvin] As a submarine pilot, you don't want to lose
communication with the surface.
That's extremely dangerous. Extremely dangerous.
Status! Status!
What the [bleep] going on where he can't hear us?
[Victor] Surface, surface.
How do you read?
Loud and clear. Loud and clear.
Crystal clear audio. I can hear him.
[Demetri] It's a critical moment in the dive.
Should Victor abandon or continue into the deep?
[sighs] Maybe it's the cold water or something.
3,000 meters from the... from the bottom.
I may just keep going.
I've come all this way.
We're gonna achieve the mission here.
I'm not gonna abort for comms out.
[Demetri] As he descends further into the trench,
it's not just the communications 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 to the surface,
I'm in a submersible by myself,
going down to the bottom of the Southern Ocean.
[rapid beeping]
[Demetri] In Mission Control, it's been two hours
since they last made contact with the sub.
Attention all stations.
Be advised that we can hear Victor
but we cannot communicate with him.
He cannot hear us.
He's very close to the lander.
[man] I'd say within a couple of hundred meters,
so he must be near the bottom.
Insulation fault. That's probably
just some water residue in there.
Everything's looking good.
I should be getting really close now.
Oh, my.
I can see something on the bottom.
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 portholes.
Surface, LF. At bottom. Repeat. At bottom.
- On the bottom. - [cheering]
[clapping]
I am at bottom.
I'm at the bottom of the Southern Ocean.
[Demetri] 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, the cameras
on the landers are still working.
They now capture Victor's arrival at the bottom.
His lights 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-strange specialists
able to endure intense cold and enormous pressure.
[Victor] See tiny white... they're like perfectly white.
They look like tadpoles.
What's that over there? A larger creature.
A little pink on the... on the top.
It has a little pink head. Two big eyes.
Oh, he's definitely swimming.
He's swimming away from my blast.
[Demetri] It seems that Victor has identified a mysid,
a type of crustacean whose bright red color
in fact makes it even more invisible
in the pitch dark of the deep ocean.
1500 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 snail fish,
this is the deepest-living kind of fish yet discovered.
And here are two new species
filmed for the very first time.
The snail fish are not here for the bait itself,
but to pick off any scavengers
the bait attracts.
Finally, the landers'
auto-release mechanisms activate,
and they head back to the surface.
But now comes the massive challenge
of safely retrieving
these 200,000-dollar pieces of equipment
in heavy seas.
- What do we got? - [woman] I think I'll just
be happy if it lands on deck.
Oh, [bleep].
The most difficult side to catch it on,
because of the arm.
[Demetri] Having lost two landers already,
the pressure is on.
[man] Charlie, we're gonna have to cross the tag lines.
[woman] Yeah.
Oh. Don't lose your balance.
[man] Oh, this thing is a nightmare.
Whoa. Got it. Got it. Wait, wait, wait.
- [man] All right, got it. - [woman] Good.
Right, what does the bait look like?
Oh, here we go.
[Alan] It's absolutely freezing.
[Demetri] The team have a vital hoard of specimens
from 24,000 feet down
whose chemical secrets could set the stage
for scientific breakthroughs in the future.
[Paul] 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 osmolyte
that we discovered in deep-sea animals
to actually cure glaucoma,
which is a high-pressure disease of the human eye.
[Demetri] Sensors on the landers
have also brought back vital information
that could confirm the root of the lifeblood current
carrying nutrients from the Southern Ocean
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.
[Hugh] The data we were very kindly given
confirm that this is Antarctic bottom water
and 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.
[Demetri] It's a breakthrough that will be vital
for future scientific work.
[Hugh] We can measure the waters flowing through
to see any change, see any signals
that are happening before it spreads out
across the whole of the world's ocean floor.
These very deep data
are gonna be very valuable for a long time.
Okay. I think that's a wrap.
Surfacing light release.
And we're heading up.
[Demetri] 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.
I'm just gonna come up slow.
Hope I don't hit an iceberg.
If I hear a thump, I'm stopping quick.
Going up. Just be patient, Victor.
100 meters to go.
[man] LF, comms check. How do you read?
[man] Yeah. Do you have visual?
Hang on.
[Victor] On surface. Repeat. On surface.
- [man] Yeah, we can see you. - I see him now, I see a light.
[man] Welcome back, Victor.
Thank you, gentlemen. It's good to be back.
[man] Xeno is inbound,
should be there in any minute.
[Victor] Roger that. Xeno inbound.
[man] We had some comm issues,
but we're gonna talk about that after.
Just glad to have you back on the surface
and just rigging for recovery.
Roger that. Comms were a problem,
but the mission was a success.
[man] Indeed it was. Indeed it was, sir.
- Great job. - [Victor] Thank you, sir.
[man] Just Nice and slow. Nice and slow.
[Demetri] The sub may be safely back on the surface,
but there's a final challenge to overcome
in the volatile waters of the Southern Ocean.
- [man] Ride that thing, Steve. - [Steve] Okay.
Oh, that was a big wave, guys.
[Steve] The LF does not like being on the surface.
It's designed to just dive.
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.
- Get it, Steve. - [man] Get down on the main.
Come on, Steve. Get... Go, go, go.
- Go! - Come one, Steve.
[man] Two hands, man.
Up on the main. Up on the main.
That's good. That's good, Patrick.
Good job, buddy.
Okay.
How you doing, Steve? You wanna get off there?
I can jump in there and do this.
Steve, let's get you off. No, he's too cold.
Hang in there, buddy.
Steve, let's get you off.
[Demetri] To prevent the onset of hypothermia,
the expedition doctor must bring
Steve's body temperature back up.
He's sat him down next to the heating duct
in the sub's hangar.
Finally, Steve's warm enough to be moved inside.
[indistinct chatter]
Yeah, they're the right color.
Keep using your hands. Good work, man.
- Thank you. - Good work.
[Steve] I've lived on the Tropic of Capricorn
my whole life,
that's close to the Equator,
I don't do cold water. [chuckles]
- [man speaks indistinctly] - [man] Welcome back, Victor.
[Victor] Thank you. Good to be back.
[cheering and whistling]
Good job, team!
[Demetri] 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. - It's good to have you back.
[Victor] Some interesting moments,
feeling quite alone
in the middle of the Southern Ocean,
but we got it done, it's good to be back.
All right. It's kinda cold.
[laughs]
Ha-ha! Thanks for getting me back.
It's a very high-tech machine that we took
to a very inhospitable place.
And 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.
[mellow music playing]