All language subtitles for The Icecup

Tonight on
history's greatest mysteries...

It is perhaps one of
the most famous expeditions

of the twentieth century.

Ernest shackleton's
disastrous mission

to cross Antarctica.

When shackleton's ship,
the endurance

got snared in polar ice,

the mission became
an all-out fight for survival.

The ship disappeared
beneath the ice.

I'm Laurence fishburn

and tonight's mystery,

what happened to
shackleton's lost ship?

Can we find it?

What secrets
might it hold?

Now for the first time,

an expedition is heading
into the frozen waters

of the antarctic.

Put it in the water!

This is pretty much
the holy grail

because it's so inaccessible.

Armed with
the latest technology...

Ready for armed state.

...and a century old log book,

they'll use sonar
and drone submarines

to track down
shackleton's famous ship.

But with winter approaching,
there is no margin for error.

Well,
what the hell is going on?

This is a start of it, here.

The hunt for
the endurance,

tonight on
history's greatest mysteries.

Antarctica,

the most extreme place on earth.

Temperatures reach 100 below.

Wind whips across it
at 200 mph.

This frozen continent
surrounds the south pole.

It's a vast land, entirely
covered in ice.

Somewhere in these frozen seas

lies the holy grail
of shipwrecks,

the endurance,

the ship that carried
legendary explorer,

sir Ernest shackleton,
south in 1914.

Down here,
the water is so cold,

the wooden ship is likely
perfectly preserved.

But it's so hard to get to

that no one's ever been able to

hunt for the wreck.
Until now.

Flying in from across the globe

is an international team
of ship hunters,

explorers, and scientists.

Two years in the planning

and over $250 million of
cutting-edge technology

make them think
they can pull off a world first.

If the data that we have for
the wreck site is correct,

then we'll find it.

Maritime archaeologist mensun
bound is heading up the search.

He's got 40 years' experience
excavating shipwrecks,

but finding the endurance
is the ultimate challenge.

The endurance is,
to my mind,

the most famous wreck
of all time.

You know, she's up there
with the Titanic.

If anybody can find
the endurance,

it's going to be
this expedition.

This is the greatest wreck hunt
that there's ever been.

The first mission
for the team members

not arriving by chopper,

is just getting onto the ship
with their gear.

Three meters, closing.

Access from a 100-ft ice cliff

is not for the faint of heart.

Okay, everyone happy?
-Yep.

Good to go.

You'll be in the center like
this, holding here and here,

-basically
-okay.

And then the other guys
will surround you.

It's quite interesting.

This expedition will face
the same risks and dangers

that shackleton did
a century ago.

But today's team
has come prepared.

The rov has the tension.

You can release it.
-Got it.

It's just going to go under.

Steve Saint amour,

leads one of the elite teams
of sub-sea explorers.

Our job
will be to document

the condition of the wreck
on the sea floor.

Based in Maryland,

his team has found
missing plane wrecks

and most famously,
surveyed the Titanic.

But hunting shackleton's wreck

is their most challenging
mission yet.

A ship has not been to the
shackleton location primarily

due to the ice pack and how
difficult it is to get here.

This is the equivalent
of going to Mars

and looking for, you know,
the wreckage of a space craft.

It's just that remote.

To help him search,
Steve's got a secret weapon.

A purpose-built,
remotely operated vehicle,

or rov.

This $2 million bot weighs in
at over 6,000 pounds.

It's equipped with
deep sea cameras

and two articulated
titanium arms.

Its mission, to dive to the sea
bed and explore the wreck.

It can descend to nearly
four miles under the water

and withstand pressure

that would crush a human
in an instant.

Before the ship sets off,

Steve's team needs to give
their robot a health check.

And so one of the things we do
to prepare for the mission

is go through and double-check
all the connections,

and tighten up hardware.

Dave O'Hara,
from northern Ireland

is Steve's pilot.

Through there.

In there.

An ex-British Navy engineer,

he's been working on robot subs
for 12 years.

We've had the
brains of the system out,

put it back in and
we'll hook her back up

and give it a test again
in a few minutes.

For me personally,
it's a bucket list job.

The shipwreck side of things
have got me inspired

to come do this for a living,
watching guys find Titanic.

Just for the history behind it,
the story,

the human aspect of it.

And I think that's the same
with endurance.

Okay, guys, just let her be.
I'm gonna start the hydraulics.

Dave's confident
he can get the sub 10,000 feet

down to the wreck.

But first they've got
to find it.

Fortunately, the team has a big
clue to where it could be.

To find the exact spot
to search,

wreck archaeologist
mensun bound

is investigating nautical charts

and the ship's original log

kept meticulously
by shackleton's captain,

frank worsley.

These record endurance's
position on the day she sank.

It gives US the coordinates,
a latitude and a longitude.

If we look at the chart,

here we have it, right here.

This is where she sank.

This is "x marks the spot."

Using the data,

mensun calculates a target
1,200 miles away

across the treacherous
weddell sea.

It's a minefield

of giant waves and jagged ice.

The weddell sea is
a churning bed of sea ice.

This sea ice breaks into pieces
and it floats around

and runs into each other,
throwing up pressure ridges,

and you never know when it will
turn totally solid again.

The expedition is
also in a race against time.

The weddell sea is
full of ice year round,

but as winter approaches,

the ocean around the continent
freezes over.

Impassable sea ice
covering an area

one-and-a-half times the
size of the United States.

The team has a short window
to get in and back out

or they'll get stuck
in the ice.

Anyone going
into that area with a ship

is putting their ship
and their crew in jeopardy.

In 1914,

two years after the sinking
of the Titanic,

British explorer, sir Ernest
shackleton, heads south.

I believe it is
in our nature to explore,

reach out into the unknown.

The only true failure would be
not to explore at all.

It's the golden
age of polar exploration.

Shackleton is full of ambition,

seeking glory for himself
and his country.

He was really driven
by the fact that

it was one of the last few
places on earth

that hadn't been touched by man

and he wanted to be one
of the first persons there.

Antarctica was the last place
to show this sense of adventure.

It was the last challenge left.

Shackleton's
aim, to make history

by crossing the entire
antarctic continent

from coast to coast
for the first time.

One hundred years ago, crossing
Antarctica was more difficult

than US going to the moon today.

I think it's the nature of man

to always see something
we haven't seen before,

whether it's the moon
or the south pole.

Shackleton
and his 27 men,

they sailed off
what we knew of the world.

But shackleton
will never even make landfall.

Here at the end of the earth,

shackleton's ship,
the endurance, will sink

in a disaster that will
capture the world's attention.

Fully loaded, the agulhas ii
finally sets off,

ready to take on
the weddell sea.

So much has gone into this
project, so many years of work,

so many dreams.

It feels like my whole life has
come down to this moment.

Now it's time to
put everything to the test.

After five days at sea,

the expedition to find the ship

of legendary explorer,
sir Ernest shackleton

is making good progress.

Now 1,500 miles
from her starting point

at penguin bukta,

the crew is zeroing in
on the wreck site.

On deck, Louisiana native
and former air force engineer,

Devon James, is part of
a second elite team

hunting the 100-year-old wreck.

It's his job to look after
a critical set of equipment,

two autonomous underwater
vehicles, or auvs.

It's basically
a drone,

just like an aerial drone,

but we use it in the ocean.

So this is used
all over the world

to survey the sea floor
without an operator

going below the surface.

Coming to you.

Also working
on the subs is Chad bonin.

Like Devon, he's ex-military.

Forward.
-Roger.

We haven't dealt with ice
conditions like this before.

We were hand picked
to come onto this job,

so there's a lot of pressure
to complete the task.

Despite the
challenges of sending their

auv subs under the ice,

Chad's got a good attitude.

As long as we're layered up
we're okay.

We're from south Louisiana,
it's usually hot weather.

The team knows
where to head,

but getting there is tough.

The expedition's hopes
rest on the agulhas ii.

Weighing in at 14,000 tons

and costing $170 million,

this ship is designed to smash
through ice three feet thick.

A double hull of extra thick
steel protects the agulhas ii,

and in the engine room,

second engineer,
Mark O'Reilly

is pushing her four engines
to the limit.

These deliver 12,000 horsepower.

This is one
of two prop shafts.

Six thousand horsepower
available on each

and that will give US
enough power to break through

one meter of ice
at seven miles per hour.

The agulhas ii is
built for the worst conditions

on the planet,

but even for this beast,

hitting ice at speed
is bad news.

Captain Freddie ligthelm,
is the ice pilot.

Part of the South African crew,

he has 15 years' experience
in the weddell sea.

If we should hit any sea ice
here at 15 knots,

it could possibly cause heavy
damage to the vessel.

So we are continuously
looking out.

The Titanic
famously sank in 1912

because it hit an iceberg
at speed.

One wrong move could bring
this ship to the same fate.

But unlike the Titanic,
the agulhas ii

has an arsenal of
modern navigational tools.

This is US here
and this is our speed vector

and you can see
that this iceberg

is at a distance of 8.8 miles.

Sometimes you could get
100 targets on the radar

at a 12-mile range,

and you would try to then just
skirt as much as you can.

To reach
the wreck site,

the agulhas ii has been sailing

around the northern edge
of the ice pack.

She will only head into the
thicker ice when she has to.

This sea ice is what explorer
sir Ernest shackleton faced

more than 100 years ago.

When shackleton took
his ship into the weddell sea,

he knew the tremendous risk
he'd never make it out alive.

Caught on camera
by photographer frank Hurley,

the endurance picks her way
through hundreds of miles

of pack ice.

But how could the 144-foot
wooden ship

avoid the fate of the Titanic
just two years previously?

Wreck archaeologist,
mensun bound,

is studying the ship's plans.

This is the original design
for the endurance.

She really was
a beautiful, beautiful vessel.

If you look at her bow,
you can see it's got

four huge oaken
timbers here.

That's two times more than any
other ship that I know of.

Her bow
is over four foot thick.

The keel or spine of the ship
is seven foot of solid oak.

And to stop her being
ripped apart by ice,

her hull is cloaked in a wood
called "greenheart",

so durable and strong
that it's heavier than iron.

It is extraordinarily hard.

It's so hard, you can't even
drive a nail into it.

But this is what
shackleton needed

because it is resistant
to the kind of wear and tear

and abrasion that this hull was
going to have to withstand

once it got into the antarctic.

Shackleton named
his ship endurance

after his family motto,

"by endurance we conquer."

And the endurance
will need all her strength

as she sails
further into the ice.

While the ice makes
getting to the wreck site

a massive challenge,

these frigid waters
are also the reason

shackleton's wooden ship
is likely preserved

at the bottom of the sea.

In warmer seas, marine
creatures eat wooden ships,

the most destructive,
a mollusk called "shipworm".

Shipworm can be incredibly
destructive to wooden ships.

And they are voracious.

They just eat anything and
everything in no time at all.

They can be up two feet long
and they just eat, eat, eat.

Recent experiments
have revealed that shipworms

can't survive in the freezing
antarctic waters.

Newly-discovered wrecks
from northern Canada

prove that icy seas can
preserve wooden ships

even older than the endurance.

But even if
it's well preserved,

the endurance
rests 10,000 feet down.

And right now, the sea there
is entirely frozen over.

For 11 days,

the expedition to find
shackleton's lost wreck

in the frozen waters
of Antarctica

has risked raging storms
and ice fields.

Now the crew is beyond
the reach of helicopter rescue.

If something goes wrong,
they're on their own.

They've reached the West Side
of the weddell sea,

as close as they can get to
the wreck site in open water.

Beyond their position
is pack ice up to 16 feet thick.

Before they break in,
Louisiana boys Chad and Devon

want to test their auv subs
under a nearby ice floe.

We're going into sea trials
where we're actually going

to launch the auv and
we'll go ahead and release it,

send it underwater.

At the wreck site,

the auvs will dive down
and use sonar

to scan the sea bed
for the wreck.

It may sound simple,

but even testing the auvs
like this is risky.

They've never been
under antarctic ice.

Auv team leader Channing Thomas
knows the dangers.

There is
a lot of pressure.

If this works,
it's going to be extraordinary.

Two years of planning
and tens of millions of dollars

rests, on the auv sub
doing its job right.

We're being extra cautious
before we put it in the water.

Once we launch it,
there's no turning back.

Alright, let's go get
US a successful launch.

Chad is taking
no chances.

Ice is a constant threat.

The fast response craft,
or frc,

is the only way he can hope
to protect

their multi-million dollar sub
at the surface.

We're on standby in frc
in case anything goes awry.

Alright, crank up hydraulics.

Yeah, we definitely don't see
this in the Gulf of Mexico.

They'll do a quick test

to make sure all of our
settings are correct,

and then send it
under the ice.

This is the start of it here.

- Auv is in armed state.
Go ahead, Shane.

They put it
in armed state.

It's armed and ready to go.

Auv in the water.
-- Like a torpedo.

Alright. Looking good.

All systems
are go.

Stay back here and monitor.

Roger that. Ready to dive.

Alright, 30 seconds
till it dives.

Come on, cowboy.

It's not going
down. Start making some waves.

It's very, very flat.

When it's flat calm like this,
it has a tough time diving.

The only way
to make the auv dive

is to make their own waves.

Go create that wake in front of
it as it's traveling.

It's trying to get the water
on top of the bow,

at the forward end of the auv
to get it to start digging in.

Go, baby, go.

Keep coming,
you're making headway.

It's going down, my man.

Good job, fellas.

It took a little
while, but it started diving.

So as of now, we have
a successful dive.

It's a great relief to finally
get it under.

We're on our first mission.

Now it's over to
Devon's colleague, Blake Howard,

to communicate with the auv.

We can pull forward
a little more.

Auv's getting down to
300 meters right now.

Once the auv gets going
on its pre-programmed

four-hour test mission,

Blake will have no control.

All he can do is track it
with this,

a high-precision acoustic
positioning system or hipap.

Dropped through the hull
into the sea,

the hipap picks
up acoustic signals

through the water from the sub.

It even pulls in
some curious locals.

While the team tracks
the auv sub,

expedition archaeologist
mensun bound

investigates how
shackleton's ship

ended up on this side of
the weddell sea a century ago.

Here he is coming down the
coast of the weddell sea,

all the while working his way
south, south.

But as he's going, the ice is
becoming more and more dense

and impenetrable,

until eventually he gets all
the way down here.

And right here is where
he becomes beset.

Just 60 miles

from the south coast of
the weddell sea,

the ice pack freezes solid
around shackleton's ship.

The endurance is trapped.

The temperature
suddenly dropped

from 20 degrees above zero
to 20 degrees below it.

The whole sea froze over
and we froze in with it.

Of course, we had no explosives
to blast our way out.

We just had picks and shovels.

For 40 hours,
his men throw everything at it.

But they can't free her
from the ice.

And at that moment,
shackleton's heart sank

because he knew, because
it was so late in the season,

that he was frozen
in place for winter.

And in the
six-month long antarctic winter,

just staying alive
is nearly impossible.

Everything
is pushing against you.

It's trying to kill you.

That cold is physically painful.

Any piece of exposed skin, just
a little gap in your clothing,

that's like somebody cutting
your face with a knife.

The wind's
unrelenting.

And the snow is driven like
needles into your face.

I was at the
south pole, it was so cold.

I removed my glove
for just about a minute,

maybe a minute and 20 seconds,

and my thumb froze solid.

When you think about shackleton
and his men, out there

in wool and cotton

and things that weren't really
designed for that environment,

it just reminds me how tough
those men were.

The endurance
is completely stuck,

but she's 550 miles from
where she will finally sink.

So how did she get there?

Turns out the endurance
is still on the move...

...because the ice
is on the move.

While it may
look like a land mass,

it's floating on water.

That means whatever
the water is doing,

whatever the wind is doing,
that affects that surface.

Strong currents
and winds in the weddell sea

spin the entire ice pack
in a giant clockwise rotation.

For ten months, the endurance
moves with the ice.

This is the route that
the endurance was carried.

We can follow the route
very precisely.

The crew was trapped,

but they had reason to believe
they would escape.

Several years before,
another ship,

a ship called the deutschland,

had also become beset
down here.

Because the deutschland
was eventually

released from the
ice,

people on the endurance thought

the same thing would
happen to them.

Out on deck in the
early hours of the morning,

the team is waiting
for their auv sub

to return from its test run.

But there's a problem.

I don't know
what the hell's going on.

They've lost all contact
with their brand new

multi-million dollar sub.

Two weeks into the
expedition

to find shackleton's
lost ship,

the team is within striking
distance of the wreck site.

But their ship
is going nowhere.

Four hours into a test dive,

auv operator Blake Howard
lost contact

with their multi-million dollar
drone submarine.

Everything started to go well,
we were gaining confidence

and then we lost it.

When we saw that it did not
surface in front of US

or to either side of US,

we figured it had to be
in the ice.

The fear is that
the auv came up

underneath the seven-mile wide
ice floe it was diving under.

The team needs to move fast.

The auv has 54 hours
of battery.

If the battery dies,
they'll never get it back.

That's a multi-million dollar
loss they can't take.

We're going to search
that area right there.

The expedition throws everyone

and everything they've got
into the hunt.

Boats,

aerial drones,

and the operated vehicles.

The auv has two flashers on it

and the general idea is
to get the rov down deep,

turn off all our lights,
and hopefully see those beacons.

Okay,
Steve, go into the water.

Bring up all
the hydraulics, please.

A cable tethers
their 6,400 pound robot

to the ship.

It gives pilot Dave O'Hara
full control.

Okay, Steve,
our depth is 30 meters.

We are at 20 meters.

Can't see very much.

Shall we kill the lights
and see what we've got?

Go for it.

Whoa, it's dark.

You know something?

There is no way we're even
gonna see a flasher.

A thick bloom
of algae beneath the ice

has reduced visibility
to almost zero.

We just couldn't
see anything.

So we aborted the dive,
come back.

Just keep the vehicle safe,
ready to try again.

Right now
I'm very worried.

From day one we recognized
that our Nemesis

was going to be the ice pack.

You know, just as
it was shackleton's,

so was it going to be ours.

And, I'll tell you what,
it's proven to be just that.

It's a setback,

but the team can't afford
to give up.

Sixteen hours later,

Blake finally detects a signal
from the missing auv sub.

I started looking at everything

and I saw that 45 minutes ago

there was a hipap hit that made
contact somewhere nearby.

The sub is within
a mile of the of the ship,

somewhere under the ice.

The first ping, when it
actually did come through,

was a great feeling
for everybody.

It's extremely exciting for her
to actually talk back to US,

and it gave US a direction
to head towards.

But with
only one acoustic hit,

team leader Channing Thomas
can't get an accurate fix.

He needs his team
to generate more hits

to zero in on the auv
sub's location.

That means a radical makeover

to their underwater
comms system.

What we need to do is
create a 45-degree angle,

so the hipap is facing
outwards instead of downwards.

Making
the comms system face forward

is something they've
never tried before.

Alright, coming down.

All stop.

We've only got
one hipap on this ship

and although it looks
to be quite robust,

in fact, it's not.

If we take just one knock
from an ice floe, that's it.

It's game over.

You know, the search for the
endurance is finished

before it even begins.

Then the team
picks up a response.

It's almost definitely a hit, so
it's got to be within range.

You know, we know
we're within its range.

Yeah, compared with

where we were two hours ago.
-Yes, yes.

Yes, sir. Exactly right.
So we're getting there.

After another
antarctic night,

the team has picked up
more new signals.

Plotted from three
different locations

to triangulate about
where she's located

and we're figuring she's
about 800 meters ahead.

Now it's not
an exact location,

but we've got a pretty good
target zone.

Half a mile
might seem close,

but the ship needs
to get closer.

Their robot
tasked with rescuing the sub,

can go four miles
straight down,

but only 400 feet sideways
from the ship.

They have to close the gap.

What are we looking at?
Three to seven meters, captain?

Yeah.

Twenty foot
thick ice is well beyond

what their ship's
built to break,

but it's a risk worth taking
to salvage the mission.

The agulhas ii
doesn't ram the ice,

it rides up onto the ice.

And under the weight
of the 14,000 ton ship,

the ice floe
starts to break apart.

The auv is about here,
about 200 meters away.

Each strike
releases colossal ice chunks

bigger than the size
of a house.

By the time they're done,

the ship's smashed away 114
football fields worth of ice.

Finally, they can attempt
a second rescue dive.

We're going
to launch the rov.

They're going to
go in and locate it

and basically they're
going to drag her out.

But what will
their rov robot find?

Across the ship, all eyes
are glued to the live feed.

Right now
we are at 6.5 meters.

In under the ice.
-- Hey, is that an auv?

That looks like one.

And we've got the auv visual.

Roger.

Tell the bridge
we've got a vis.

Finding
the auv is a huge relief.

But now they need
to bring it out.

You can see the end
of the auv with the prop.

So it's definitely in a crack.

Dave has to grab
the auv with the robot arm.

So you're pretty much
gonna have to fly me into it.

Come on, bubba.

Slow, slow, slow, slow.

As soon as we
started the move

the fish dropped
away below US.

We gotta go chase
the fish down.

Getting back in there.
We'll have to try again.

Every missed
attempt pushes the auv

farther out of reach.

And at the surface,

moving ice is threatening
to snag the robot's tether.

The team needs
a new solution and fast.

Four days ago,
the expedition lost contact

with their multi-million
dollar auv sub.

It's a vital tool
in their hunt

for shackleton's
lost antarctic wreck,

but it's now 1,500 feet below
the ship on the sea floor.

Yeah, your heading's good.

Sub-sea explorer
Steve Saint amour,

is sending the robot
back down to locate the auv sub

and attempt a rescue.

At this depth, the weight of
water pressing down on the auv

is equivalent to two jumbo
jets, one on top of the other.

The robot's got a hook and line,

but pilot
Dave O'Hara is finding

that fishing at this depth...

...is far from easy.

The hook has to hold.

Yeah, copy.

You can probably get
the bridge to start moving

real slowly forward now, mate.

After four days,
the auv is finally in hand

and on the way up.

But as it approaches
the surface,

Steve halts the ascent.

Bridge, go ahead.

All the ice floes
and bergs

that we've broken off overnight

are all just sweeping in
and around US.

The rov will get caught
in some of these bigger floes.

Ice chunks this
big can weigh 2,000 tons,

more than 13 blue whales.

If one of them hits the cable,

the team could lose their robot
and the auv sub.

Roger.

Finally,
the path is clear.

I just got to get it
up to surface.

The rov has the auv
in its grasp.

It's coming back up.

Frc, rov
approaching surface.

Alright, here we go.

You got a hold of it?
-Yep.

Alright,
back down a little bit.

Whoo!

That's cold, buddy.

After a very
close call, the auv is safe.

Alright, coming up easy.

We're good.

Got it, Paul.

That's it.

I'm just glad to
have it on board.

It's been a rough
four or five days,

so it will be nice to actually
get a full night's sleep

instead of a few hours
here and there.

With the critical
gear now on board,

the hunt for the wreck
is back on.

Yeah, this is great.

Having her back on board
like this, it's the best.

The team can
now press ahead.

But there's still 230 miles

from where shackleton's
ship went down.

And in that area, the sea is
still entirely covered in ice.

Shackleton and his ship drifted
into this Northwestern part

of the weddell sea,
in October 1915.

For 10 long months,
they've been locked in the ice

in a bitter struggle
for survival.

It's so damn cold.

If you don't have an elaborate
safety net of equipment,

you'll die.

Shackleton's
only safety net is his ship,

but now the mounting
pressure in the ice

is breaking it apart.

They're in the ship,
they can hear this ice

moving against the ship.

You hear the creaking
of the ship.

You hear the pressure
on the joints.

You never know if the ship's
just gonna break apart.

The timbers began
to crack and groan.

It was like heavy fireworks
and the blasting of guns.

To see
the pack ice move in

and just squeeze the life
out of that boat,

it must have been so trying
and so depressing.

Mother nature
overwhelms the mighty endurance.

Finally, shackleton gives
the order to abandon ship.

Their only hope was to
take everything off that ship

that they needed,

and put it on their rescue
boats and then

switch into survival mode.

The 28 men
and 49 dogs

can only watch as
the endurance is overwhelmed.

I can only image what it was
like for him when he sat there

and stood on the ice and watched
it just slowly implode.

Just a piece of his
heart and soul

probably went down
with that ship when it went.

The ship
disappears beneath the surface.

Shackleton and his men
are truly alone.

I think they were much more
lonely than I was on Apollo 13,

because I had
communication with home.

Shackleton, he didn't have
a radio, he didn't have Wi-Fi,

didn't have, you know,
a cellphone.

He was alone.

Shackleton's
dream of becoming

the first man
to cross Antarctica

is ultimately crushed
along with his ship.

This is where his real battle
for survival begins.

But if the ice crushed
shackleton's ship,

what can the team expect
to find on the sea floor?

Mensun bound is searching
for clues in the records.

You see in this
picture here,

the stern Rose up 45 degrees,

the bow went even further down

and then she just slid
and was gone in minutes.

The endurance
then dives

10,000 feet to the sea floor.

But mensun spots evidence

that the wooden ship likely
survived the impact.

All this clutter that you see
in this picture here,

all these masts and yards,

all that was still attached to
the ship when it went down,

and that would have
imposed an incredible

drag on the sinking ship.

That would've kept her upright
and would to some extent

have slowed her down.

I do believe
that the ship itself

is likely to be
in an upright state,

but also
three-dimensionally intact.

It's promising
news for the rest of the team.

But suddenly,
there's a new problem.

This time it's not the auv sub,

but the robot that's supposed
to explore the wreck.

The pod's gone.

It looks like
it's suffered a death blow.

Halfway into
their mission time,

the team in Antarctica
is under mounting pressure

to reach the site
of Ernest shackleton's wreck.

Engineers Steve Saint amour
and Dave O'Hara

are depth testing
their underwater robot

so it's ready to go.

But something's not right.

Guys, we're gonna bring it back.

The pod's gone.

A critical part
has imploded

under the extreme pressures

ten thousand feet
below the surface.

The robot's electronic brain
is now mangled metal.

We've had
a catastrophic failure.

We don't have all the
electronics to rebuild the rov.

I don't know what to say,
really, I just don't.

Yeah, I'm speechless.

The aluminum pod

was designed to
withstand pressure

nearly three miles
below the surface.

But Steve thinks
the combination of extreme cold

and a material flaw

has caused it to be crushed

like it was nothing more
than a soda can.

This is what we found.

One half of the bottle
has pancaked

into the other half
of the bottle.

There were
quite substantial electronics

and they are entirely crushed.

This is the first time
in my career

that I've ever seen
this first hand.

This is an example of what
hydraulic pressure can do.

It's a bitter blow
for expedition archaeologist

mensun bound.

The worst possible news.

I mean, to lose our electronics
like that.

There is no replacement.

We can't fly in spare parts.

There's nothing we can do.

This was what I was going to
use to study the wreck, really,

eyeball to eyeball
with the wreck.

To add
to the problems on deck,

the bridge has discovered their
closest route to the wreck site

is now totally shut off
by the ice.

Analyzing daily satellite
photographs,

ice pilot Freddie ligthelm
is hunting for another way in.

He's looking for channels
of open water called leads

on the other side
of the pack ice.

It does appear that
there's some leads opening up

in that area, so we're quite
excited about that.

We can actually approach the
search site coming right around

all the ice and approaching
from the south east.

With a bit of luck, we can be
cautiously optimistic.

The new plan
is to go the long way round,

skirt the pack ice, and then
head towards the wreck site.

With a clear path
ahead of them,

the ship should be able
to reach the wreck site

in a matter of days.

Out on the deck, the auv team is
making their final preparations.

All hopes now rest on them
to find the wreck.

I'm excited about it.

Can't beat the smile off my
face right now, you know.

Finally getting there.

To be in the same area
where he was at

and to finally locate that ship
is just...

It's an excitement
that I really can't explain.

Finding
shackleton's ship is the

ultimate goal of
this expedition.

But 100 years ago,
losing the endurance

was just the start of a journey

that would make
Ernest shackleton a legend.

Stranded on the ice,

shackleton's men face
impossible odds,

but they have blind faith
in the man they call the boss.

There's this classic quote,
and to paraphrase it,

"when the chips are down
and all hope is gone,

"get down on your knees
and pray for shackleton."

Shackleton orders
his men to march for land,

two hundred miles
across the ice.

Shackleton has
these massive sleds

with full wooden boats on them
loaded with supplies.

And you could come up to
a massive pressure Ridge,

blocks of ice
as big as semi-trucks

that are shoved
up into the air

ten, 15, 20 feet,

and so,
as you're approaching it,

it basically is a wall of ice.

I mean, I don't like to say
things are impossible,

but I don't know how they
would get over that stuff.

The men cover only
nine miles of pack ice

in a week.

Shackleton realizes
reaching land is impossible.

To make matters worse, they're
slowly starving to death.

As food supplies run out,
they're forced to eat

the only things that brought
them joy in the wilderness,

their dogs.

The companionship
that the dogs provided the team

was quite significant.

That moment must have been hard
in an emotional point,

but it was also a mirror
of how extended they were

and how precarious life was.

If you're shooting your dogs,
you're on the down and outs.

Then,
as the ice they're on

drifts closer
to the open ocean,

it starts to break apart
beneath them.

And they have to rush
onto their boats.

They have to throw
their things on their boats.

They have to get
into these boats

with everything they need
to survive.

They have no choice,
but to go from relative safety

to basically certain death.

Shackleton
has finally left the ice

that's trapped him
for 15 months.

But now he faces a new danger,
the open weddell sea.

Even today this sea is nearly
impossible to navigate,

as the crew of the agulhas ii
is finding out.

We are now just stuck.

To reach the site
of Ernest shackleton's wreck,

the agulhas ii has powered
around the ice pack

at the heart
of the weddell sea.

And she's smashed through
thick ice for the last 24 hours.

But just 19 miles from where
the endurance sank,

the agulhas ii runs
into serious trouble.

She's stuck in the ice
just like shackleton's ship.

- We're stuck.
We're in a white out.

The ice is well over
three meters thick,

possibly even as much as five,

and we're way, way below zero.

In the early
hours of the morning,

the ship was brought to a
standstill by impenetrable fog.

The ice moved in around her
and froze her in.

If the temperature
drops further,

the ice could trap the crew
for days,

and the harsh antarctic winter

is already barreling
down on them.

But Devon's got an idea.

We could do like
shackleton did on the endurance

when they got stuck in the ice

and had the whole crew run
from one side of the vessel

to the other, together,
to rock the ship free.

Devon's
half kidding

but his plan
isn't as crazy as it sounds.

Captain bengu has 18 years'
experience in antarctic ice

and he's got a 21st-century
trick up his sleeve.

Instead of moving his crew
from one side to the other,

he's shifting a 40-ton
container of fuel

using his crane.

And in
the engine room,

engineer Mark O'Reilly
is firing up

the two propellers
to maximum power.

After 14 hours using its crane,

and its 12,000
horsepower engines,

The agulhas ii
finally breaks free.

Sounds like
we're moving again.

See, you can hear the distinct
difference

in the sound here, you know.

That's definitely ice scraping
alongside the vessel

as we're moving forward.

And now
that the fog has lifted,

the captain has a clear view
of the route ahead.

But the ship still has to get
them inside the wreck zone.

And the closer they get,
the thicker the ice becomes.

This really is
shackleton territory.

The ice here is old,

it's gnarled,
it's all hummocked

and it's all raftered up and
steepled up into these ridges.

It's amazing that
those guys survived

as long as they did
on ice like this.

It's incredible.

This is the ice
that trapped shackleton

and his men for 15 months.

When they finally escape it
on life boats,

they have to battle
freezing winds and ice storms

on the open ocean.

Shackleton sets out
for a tiny island 60 miles away.

It's his final hope.

On the seventh day at sea
and barely alive,

they miraculously spot land.

And when they saw
elephant island,

everybody cheered.

And we pulled as hard
as we could to make our landing.

But it was
a weird sort of euphoria

because they hadn't
made it home,

they had made it onto
an inhospitable rock.

The first night there,
what was left of their tents

was just shredded
in the wind.

Humans were not
meant to be there.

The whalers
didn't even come by there.

They are on a tiny
storm battered

pinprick of a rock.

Of course,
food was very short.

We had very little except
a little seal and penguin

whenever they came up.

Shackleton knew
the men could not survive.

Conditions would
only get worse.

He had to get help,

and he knew he had to go
as quick as possible.

But the only
way out is across

the most dangerous ocean
on the planet.

Taking only five men,

two barrels of water
and four weeks of food rations,

shackleton launches
their largest life boat,

the James caird.

There's a picture
taken by Hurley

with a little brownie camera,
with the little camera he had.

That picture scares
the bejeezus out of me.

This tiny speck of a boat,

them all waving bravely at them

as if to give them
encouragement.

Most of them must have felt,

"they're never going to make it

"and we're never
going to be saved."

Shackleton's
plan is to

head to the island of
South Georgia,

eight hundred miles across
the southern ocean.

The southern ocean is probably
one of the most treacherous

bodies of water on this planet.

It's not uncommon to have
winds in the 50s, 60s, 70 mph,

swells up to 100 foot.

The water temperature is
just a little above freezing.

It can sink a vessel
in seconds.

It's like going up
a hill or a mountain

and you go up and up
and then you reach the top

and then you go down
and you skid down.

The odds
are stacked against them,

but shackleton knows if
he doesn't make it to land,

all his men will perish.

A century on,
after two years of planning...

This is the point
where she went down.

...five and a half
weeks at sea,

and four days battling
the ice...

...the agulhas ii
has finally broken through

to the exact coordinates
of the endurance wreck site.

It's a major achievement.

Only a handful of ships
have ever been here.

It feels great. I was
up on the bridge till late.

I only got two hours' sleep,
I'm shattered,

but, you know, at the same time
I'm really happy.

But, you know,
we've still got to find it.

To actually be here and able
to be part of the search

is very exciting.

I'm ready for it.

But can they reach
the endurance?

Deep within the
iciest part of the weddell sea,

against all odds,

the expedition to find
shackleton's wreck

has broken through
to the actual site

where the ship sank
over a 100 years ago.

Steve and Dave's robot sub
is out of the game.

Damaged beyond repair,
it can't hunt the wreck.

But there's still the auv sub,

which will use sonar
to scan the sea floor.

We're close to the actual
last known location

of the endurance.

We're gonna launch
from where we're at,

all the way down to
3,000 meters, to the bottom.

Hopefully everything works well,

according to plan,
and we'll see what happens.

Existing scans
reveal that the agulhas ii

is floating above
a vast underwater plain.

Here the sea floor plunges down

forty times the height
of Niagara Falls,

to a depth of 10,000 feet.

This is the deepest zone
of the weddell sea,

and the crew believes
this plain

is the final resting ground
of shackleton's ship.

To program
their sub's flight path,

the team needs to know what
the water conditions are like

at the sea floor.

They deploy a monitoring device
called a ctd

to analyze the water.

Somewhere
in these icy depths,

ten thousand feet down,

lie the remains
of shackleton's ship.

Mensun bound wants to know

what the data
might also tell him

about the condition
of the wreck.

Hey, guys, what have you got?

This is the ctd
over the wreck site

and it's just got to
the bottom,

so we're at about
just over 3,000 meters.

And as we get
right to the bottom,

sort of in the last couple
of hundred meters,

the temperature
goes down considerably.

Remarkably,

the water at the sea floor
is below 32 degrees.

It doesn't freeze solid because
of the vast pressures at depth.

Depth combined
with the super cold water,

any bacterial activity
will be slowed down.

This is all pretty good news

for the preservation
of the endurance.

All they've got
to do now is launch the auv sub

to hunt it down.

Hit that hydraulics
when you walk around.

But all the ice here
is a problem.

The auv normally needs an open
run of several hundred feet

to get below the water.

To make it sink faster,

Devon and Blake are trying out
an unusual solution,

using a bag of salt
to add weight.

But will their
improvised fix work

when it comes to
the actual launch?

I've added
five kilos of salt.

Salt should help it get down
in this flat calm water

and get down to bottom,
and start tracking.

Ready for armed state.

It's heavy.

Alright.

Adding the salt
is a success.

The propellers bite
and the auv dives.

That was a successful launch
for the first mission

to search for the endurance.

If all goes well
on the mission plan,

we should be recovering
in about 42-43 hours.

If it's down there,
we should be able to find it.

Fingers crossed.

So far, so good.

The plan now is for the auv

to spend the next 43 hours
away from the ship

on a pre-programmed route
beneath the ice.

At the moment we've just got
to depth, almost 3,000 meters,

and we just got comms
with the auv.

Everything's good. She's where
she's supposed to be.

Channing's team
checks in with the auv

at regular intervals

using the underwater
acoustic comms system.

That's a very big relief
that she's not

given US issues
underneath the ice.

So everything's looking good
at the moment.

We're gonna
keep our fingers crossed

and keep thinking positive
and keep pushing forward.

Now the ship
must follow the auv

no matter how thick the ice.

After over 100 years,

the hunt for shackleton's wreck

comes down to what happens
in the next 40 hours.

The team
has succeeded in reaching

the exact place sir Ernest
shackleton lost his ship.

Now can they find it?

Ten thousand feet down,

the auv sub is halfway
through its mission.

She's proceeding
onto line three

and we're actually
gonna jump up to that line,

find a nice comfortable spot
in these floes

and wait for her there.

For now,

auv team leader Channing
Thomas and his team

can only follow their sub's
programmed route.

Roger.

We monitor it
still on that line

as long as we can
to make sure she's flying true

and straight
and at the right altitude.

Much like
on an airplane,

all the scan data from
the auv sub

is recorded onto a black box
stored on the sub itself.

Devon will only find out
if it's found the wreck

once they pull it out
of the water.

But that won't be
for another 24 hours.

Five months
after losing his ship,

shackleton faced
impossible odds in Antarctica.

He left 22 men behind
on elephant island

and he's braving the worst
ocean on the planet.

But after battling across
800 miles of it in two weeks

and painfully dehydrated,

he finally spots the island
of South Georgia.

They'd made it.

They had made the toughest
crossing in the world

in a vessel that never made
that crossing before.

There was a sense of euphoria.

From his landing
point at king haakon bay,

the closest settlement is a
whaling station,

30 miles to the east.

But blocking his path now
is a towering mountain range.

The mountains
were covered with snow and ice

and to get some sort of
traction on the snow,

they took nails out of the boat

and pounded them through
the bottom of the shoe.

Mountaineer
Conrad anker

has followed shackleton's route.

Shackleton's
traverse of South Georgia,

in the context
of when he did it,

was certainly one of
the most technical climbs

done in the mountains.

If they didn't make it,
their men were going to die.

And when you have that degree
of immediacy on your goals,

you get things done.

After climbing
for 36 hours,

shackleton finally limps
into civilization.

When shackleton
told his story

of what they'd been through,

no-one at
the whaling station,

they couldn't believe it.

Every step of this story
was beyond belief.

But, of course, it wasn't over
for shackleton then.

He had to go back and save
the people on elephant island.

Shackleton strives
tirelessly for four months,

to break back through
the frozen sea.

At last,
he approaches elephant island.

And as he's going ashore,

the men on the island are
seeing the rescue boat is here

and they're starting to come
out from under the shelter.

And shackleton is counting,
"one, two, three, four,"

all the way up until
he's counted everyone.

And he looks to worsley
and says,

"they're all there,
they're all alive."

And the emotion
that he had at that time,

had to be just overwhelming.

To bring everybody on
his expedition back home alive,

was probably one of the
greatest adventure achievements

that we have
in our history books.

On board
the agulhas ii,

the crew hunting down
shackleton's wreck

has suffered a major blow.

Thirty hours into the dive,

the auv that's scanning
the seafloor has gone missing.

The multi-million-dollar
machine

has likely located
the wreck.

But auv operators
Devon and Blake

have lost contact with it.

If they can't reconnect,

they'll never find out
what's below.

We've gotten over the site.

We've got the best equipment
and opportunity to find it

and if we can't recover
the data

after the auv has already run
its mission,

that's kind of heart-breaking.

Devon's last
hope is that it's waiting

at its rendezvous point,

ten miles away,
600 feet below the surface.

But they need
to get there fast.

The auv's battery
is running down

and once the battery dies,
the auv's nothing more

than a 4,000-pound paperweight.

The problem is,

getting anywhere out here
is far from easy.

Twelve hours into the chase,

the agulhas ii grinds
to a halt.

We're stuck.

In normal conditions
with open water,

we'd just shoot over
to the loiter box,

pick her up
and everything would be fine.

But, yeah,
right now we can't move.

We're now almost eight nautical
miles to get to the spot

and her battery is running out.

It's tough to search for an auv
in this kind of situation.

The team
doesn't have time to wait.

Last time the ship got stuck,
it took 14 hours to escape.

If it takes that long again,

the sub's battery will be dead
before they reach it.

It's just a waiting game.

It depends on how long we got,
we need to wait,

so, hopefully,
not too much longer

because we are losing time.

At last,
the ship breaks free.

By the time the agulhas ii

makes it to
the planned end point,

the auv's only got
four hours of battery left.

The team prepares to lower its
main communication system.

Yeah, we're just gonna get it
together here,

spin it and then lift it.

But there's
no signal.

The auv is not where
they hoped.

There's just
one last possibility.

Has it come up
and gotten stuck under the ice?

Devon and Blake
want to use another device

to boost the comms system.

We're gonna drop this
transponder down into the water

and bounce the signal
possibly to the auv.

At this point,
any response is good.

They need to pick
up a signal from the sub.

This is the last known
possible location.

I'm 50/50.
-Yep.

It's a crap shoot.

It's the team's
final roll of the dice.

But what will they find?

At the site
where Ernest shackleton

lost his ship a century ago

the team sent to find it

has a tough call to make.

Their final attempt to locate

their multi-million-dollar
auv sub has failed.

We got there and we could
not establish communication

and we started realizing
it's not here.

Without the auv,
the hunt for the wreck is over.

It hurt. You know?

The auv
could be anywhere.

It's likely out of battery.

And temperatures
are dropping fast.

The ice floes that have trapped
them twice in the last 48 hours

are closing in.

If they don't get out soon,

the ice could trap them
for weeks,

just like the endurance.

Captain bengu makes the call.

I personally feel we've...

We've done exceptionally well

under the circumstances.

I think we just accept
and let go.

We are at the end
of the season now.

This is where the ice
starts forming first

and, yeah, we should
certainly get out of this area.

Antarctica's
a tough cookie to crack.

Shackleton figured that out.

Obviously we're figuring it out.

The antarctic
has already cost the team

one of their auv subs

and destroyed
their underwater robot.

We came down
with bigger, better technology,

but the same rules
that shackleton was playing by,

still apply today.

You know, mother nature,
at some point

puts her foot down
and lets you know who's boss.

The ice still rules.

The ice is still the king
and you have no choice.

You're merely there
trying to do the best you can.

For now, the
secret of shackleton's lost ship

remains locked in the auv,
hidden beneath the ice.

The auv
could be anywhere.

At this point
it's likely that it's buoyant

and floating under the ice.

That information
that's on that auv,

could hold the secret
of the endurance.

We were always
up against the ice.

That was always
the enemy for US,

just as it was for shackleton.

And, yeah,
it's beaten US also.

The loss of the
endurance a century ago,

turned shackleton
into a legend.

Shackleton resonates today

because of keeping
his men together,

keeping morale up,
doing the impossible

and then saving them.

That's endurance.

Whenever I'm out there
in a tricky situation,

climbing or where things
might not be going my way,

I take a bit of shackleton
and I plug it in and i'm, like,

"yeah, sir Ernest shackleton,

"he would persevere."

And that is the power
of shackleton's story.

On the hunt
for shackleton's wreck,

the crew has battled
the same conditions

faced by the endurance,

broken through to one of
the most remote places

on the planet,

and explored
for the first time,

the ship's final resting ground
on the sea floor.

For the expedition,
getting this close to the wreck

is a major feat of exploration.

And while the onset of winter
marks the end of this season,

the team plans to return.

If there's an opportunity
to come back

and search for it again,
I'm gonna be first on the list.

Hopefully
we'll find the auv

and shackleton's ship
in the same spot.

I always said this was
the greatest wreck hunt

that there's ever been
and still is.

I mean, somewhere beneath
my feet is the endurance.

And do you know what?

It isn't over yet.

To be able to go down
and find it and locate it

and document it,

would be a closure for
this whole endurance story.

Though polar ice has forced the
team to retreat for now,

they are determined to one day
return and find at last

shackelton's lost ship.

I'm Laurence Fishburne,

thanks for watcing

history's greatest mysteries.