All language subtitles for Mysteries of the Deep Series 1 2of6 Nazi Toxic Hell Sub 1080p

Wade: In the aftermath
of a tsunami disaster,

Can underwater robots succeed
where no humans can go?

Tuttle: This is a robot in
highly radioactive water,

And it's, like,
three levels bad.

Wade: How did a shipwreck end up
perfectly preserved

On the bottom
of the great lakes?

She is completely intact.

It was almost as if it had been
sort of gently placed

On the bottom of the lake.

Wade:
And what's the dark secret

Buried inside
a toxic nazi submarine?

There is a ticking time bomb
at the bottom of the ocean here.

Wade: The underwater realm
is another dimension.

It's a physically
hostile place,

Where dreams of promise
can sink into darkness.

I'm jeremy wade.

I'm searching the world
to bring you the most iconic

And baffling underwater
mysteries known to science.

Shipwrecks can't
just disappear.

Or can they?

Wade: It's a dangerous,
unexplored frontier

That swallows evidence...

We know more
about the face of mars

Than we do our deepest oceans.

Wade:
...Where unknown is normal

And understanding is rare.

-- Captions by vitac --
www.Vitac.Com

Captions paid for by
discovery communications

♪

♪

The most extreme force
in the ocean, the tsunami,

Has killed hundreds of thousands
of people over the centuries

And wrought destruction
across the planet.

And the most powerful man-made
force on earth, nuclear energy,

Has wrought destruction
and death in equal measure.

So what happens when
these two forces meet?

In japan, this clash has led
to a toxic mystery

That science is still
struggling to solve.

♪

March 11, 2011,

Approximately
45 miles east of japan,

Deep beneath the pacific,

A magnitude 9,
mega-thrust earthquake

Rips through the ocean floor.

Barrett:
Japan is basically sitting

Right on top of the pacific rim,
the ring of fire.

It's a whole series of deep,
underwater trenches,

Where one tectonic plate
is moving underneath another.

The pacific plate goes
under the japan plate,

And it snapped up,
almost 100 feet in places.

♪

Wade:
The earthquake is so powerful,

It moves the main island
of japan 8 feet to the east

And shifts the earth on its axis
by over 6 inches.

It was the largest earthquake
they recorded there

In many centuries.

Wade: But this natural disaster
is only just beginning.

The earthquake created
a huge series of waves,

Tsunami waves, or tidal waves,

That basically raced toward
the mainland of japan.

Wade: 45 minutes later,
waves over 40 feet high

And traveling in places
at speeds

Of several hundred miles
per hour, hit the land.

♪

The harbor has
this tsunami wall.

And you just see
the water rise up,

Go to the top
of that tsunami wall

And just pour over
into the town.

Wright: Cars are flipped around
like toys,

Buildings are completely flooded
and smashed,

People are swept away
at a moment's notice.

It's just a nightmare.

♪

Tuttle:
They were prepared for tsunamis.

They were not prepared
for that tsunami.

Narrator: Sitting right in
the path of the oncoming tsunami

Is the fukushima daiichi
nuclear power plant.

♪

♪

Barrett: It flooded the plant,

Much higher
than they ever expected.

The plants were designed
for a 18-foot-high tsunami wave.

What actually hit them
was 45 feet,

So it was three times higher
than they ever expected.

It's an absolute disaster.

Who could anticipate something
like this?

Wade: The angry ocean torrent
floods the emergency generators,

Cutting electricity
to the cooling system

That keeps the nuclear reactor
cores at a safe temperature.

Barrett:
And the cores overheated,

The gas built up inside,

The pressure's increased
because they could not cool it.

It ignited with a spark
somewhere,

And two of
the buildings exploded.

♪

Wade: All three reactor cores
largely melt.

Then, like lava from a volcano,

They pour through 6 inches
of steel

At the bottom of the reactor
and down into concrete.

I refer to it as hell on earth
sometimes,

Where there was operators
in the control room,

In the dark,
wearing protective equipment,

You know, trying to figure out,

You know,
what they were gonna do.

[ alarm blaring ]

Wade: Millions of gallons
of seawater

Are urgently pumped in

To cool the core temperatures
down to a safe level

And prevent the release
of more radioactive gas.

The biggest concern in this
situation, of course,

Is the sort of exposure
and release

Of radioactive materials
from the nuclear facility.

Wade: Leaks from the plant
are not without precedent.

In previous spills, thousands
of tons of contaminated water

Have leaked into the ocean,

But it's the water around
the destroyed reactors

That poses the most
immediate problem.

There's different levels
of water in the three reactors.

One of them is --
the water level is low,

The other one the water
is about 2 feet deep,

And the other one
it's about 9 feet deep,

So the molten core is underwater

And there's always water being
injected on it to keep it cool.

Wade: Not only did water
cause untold damage

When it consumed the plant,

It's now stubbornly getting
in the way of the cleanup,

And it's incredibly dangerous.

You have all this water around
that radioactive material,

Which, in itself,
becomes radioactive.

Wade: Sending divers into the
radioactive underwater areas

Is not an option.

Barrett: The radiation levels
are excessively high,

So, you know,
it'd be fatal to go inside.

Wade: So another solution needs
to be found, and fast,

Because until it's contained,
there remains

The risk of radioactive
runoff leaking into the ocean.

How do the japanese take care
of this environmental disaster

Waiting to happen?

♪

Years after a tsunami

Floods the fukushima
nuclear facility,

Almost 1,000 tons
of radioactive material

Lie scattered and submerged in
the bowels of the power plant.

Can new technology speed up
the critical cleanup operation

To halt the spread
of radioactive contamination

To the ocean?

With the distance of the pacific
being just 100 yards,

Another earthquake
could very easily cause

A disaster far greater
than this one.

So the team is under
a constant pressure

To get the control
of the radioactive material

And get it to a safe place.

They're not cleaning up, they're
figuring out how to clean up.

Wade: Technicians are struggling
to solve the problem,

But so far, they've been unable
to even reach the reactor cores.

It requires technology
beyond cleaning crews

And human cleanup.

Wade: This is not a first.

In 1979, the three mile island
facility in pennsylvania

Suffered the worst nuclear
accident in u.S. History.

Lake barrett was a director
of the plant.

In the case
of three mile island,

We had several million gallons
of highly radioactive water.

We had to develop specialized
cleanup systems.

Wade: Faced with a molten core
submerged in water,

Lake's team employed
a pioneering solution

For the time -- robots.

We had robots at three mile
island, very crude robots,

1980 robots.

We were able to develop

The equipment
to remove the core.

And over
the next seven years of work,

It was successfully removed.

Wade: But this operation

Required international
assistance.

We were reaching out
to the world for help,

And only one country
in the world

Came to our aid
and that was japan.

So when I was asked
to help them,

I felt it necessary to do that.

Wade: Could the solution
found in the u.S. -- Robots --

Be the answer at fukushima?

In theory, this sounds
pretty straightforward.

Let's create some robots
that can go in

And photograph and clean up.

The practical reality is
much more complicated.

Wade: The meltdown caused
by the tsunami

Has created a no man's land
inside the reactors,

An uncharted lethal landscape,
much of it underwater,

That the robots
will need to navigate.

The robots have to be small
to go inside the reactor vessel,

And it's complicated work
to get these small ones to work

And do what you want.

Wi-fi and radio signals
do not work in there

Because of thick, reinforced
concrete walls.

Wade:
Finally, a robot is ready.

Known as scorpion, it has cost
tens of millions of dollars

To develop
and put into operation.

Barrett: They had a --
the camera would come up

Like a tail of a scorpion
over the front.

It went about 10 feet,

And it got caught on debris.

It couldn't get down
into the molten-core area.

This was a multi-million
dollar mistake.

Wade:
It's back to the drawing board.

Other robots follow
but with limited success.

They were supposed to work, we
thought, for about eight hours.

They worked for about an hour
and a half before the radiation

Basically fried
the circuits inside.

Wade: The robots fail to get
near the reactor cores.

You learn more from a failure
than from a success

In many ways.

Wade: Eventually, designers come
up with an underwater robot

Called little sunfish.

Its task is to navigate into the
heart of the flooded reactors.

Barrett: The sunfish was a
small, tethered submarine

With cameras on it,

About 5 inches in diameter,

That had to swim down
through a little doorway

Underneath the reactor vessel.

Wade: Sunfish enters an
underwater realm like no other.

♪

Finally, it glimpses something
through the murky water...

...Almost stalactite-like
formations

Dripping like candle wax.

Barrett:
You could see pieces of fuel

And you could see,
you know, molten debris.

This was the first time
we got to see that,

So everybody was very excited
about the success of it.

Wade: With this breakthrough,

The cleanup team
can now look to build bigger,

Muscle robots
to remove the debris.

Clarke: Without this technology,
without robots,

This would not be possible.

Wade: But developing
and deploying

This advanced robot fleet
to clean up fukushima

Is a major,
long-term challenge.

The cost of this
is going to be large.

It's going to be about
$200 billion,

And the technical cleanup
of the site itself

Is going to be multi decades.

Wade:
Until the cleanup is complete,

Fukushima will remain
a potential radioactive risk

To the neighboring ocean,

And the ocean itself
remains a clear

And present danger to the plant.

Clarke: What happens
if there's another earthquake,

Another tsunami,

And we haven't dealt
with this in time?

♪

One thing we do know
is that we underestimate

The forces of nature,

Whether the untamed power
of the ocean,

Or the harnessed energy
of the atom at our peril.

♪

I've dived
on numerous shipwrecks,

And many are just that --

Rotted, rusting wrecks.

But on rare occasions,
the depths offer up

That holy grail
of marine archeology --

The wreck
that's perfectly preserved.

With all the evidence intact,
unraveling the mystery

Of what happened to the ship
should be easy,

Or so you'd think.

♪

1986, lake huron,

The second largest
of the great lakes.

Shipwreck hunters
are exploring the waters

In the northwest of the lake

When they make
a jaw-dropping discovery.

A schooner, more than
100 years old,

Frozen in time on the lake bed.

She is completely intact.

Tuttle:
The masts are still up.

The rings that hold the sails
that go up the mast

Are still in place.

The cargo of grain
is still in the hold.

I mean, this vessel is
in pretty spectacular condition.

It was almost as if it had been
sort of gently placed

On the bottom of the lake.

Wade: What sank this perfectly
preserved wreck?

A perfect, undamaged shipwreck
has been found

At the bottom of lake huron,

But what happened to her?

How is it that this great ship
is pristine in condition,

Resting on a lake bed?

Wade: On the ship's side,
divers discover a name,

The cornelia b. Windiate.

She's a 136-foot schooner
that went missing with all hands

During the November
storm season of 1875.

The great lakes take
their fair share of ships.

Wade: 6,000 shipwrecks litter
the beds of these huge lakes

And over 30,000 lives
have been lost.

If a vessel's in a storm,

Usually that storm creates havoc
on the vessels.

You know,
it can rip things off the deck,

Tear things apart,
bust masts, things like that.

None of that is seen
on the windiate.

Elliott: If that ship had sunk
in a storm,

You'd expect it
to be smashed to pieces.

Wade:
As well as no signs of damage,

There are no signs of any crew.

Elliott: We don't know
where the crew are.

There are no bodies
associated with it at all.

Wade: But we do know

That they didn't make
a standard maritime escape.

Lying in perfect condition
on the lake bed

Is the schooner's
single lifeboat.

What happened to the windiate
and her men?

Goodman: One thing is certain --
the ship sank.

Why or how it sank is
a little bit more unclear.

Wade: In the 1870s,

Lake huron was part
of a valuable grain route.

Tuttle: We know the vessel
left milwaukee

Loaded with tons of grain.

She was heading to buffalo,

One of the great grain centers
on the eastern great lakes.

Wade: A November sailing
carried weather risks,

But with fewer voyages being
undertaken at this time of year,

It's likely there would
have been a financial incentive

For the crew.

The area depends on
this kind of trade,

And there would be nothing worse
than a bunch of rotting grain,

Especially at the end
of the season.

Wade: It appears
that the windiate

Was leaving nothing to waste.

Port records show
that on departure,

She was overloaded
with 30% more cargo than usual.

During her voyage, the windiate
would likely have encountered

Gale-force winds

And temperatures down
to minus 10 degrees or colder.

So is it possible
that the freezing weather

Provided an unexpected escape
route for the missing crew?

Goodman:
Because it was cold weather,

Perhaps the ship itself
got stuck into ice,

And the crew tried
to leave the ship.

Wade: Such an escape
is not without precedent.

In winter, the great lakes
are prone to freezing,

And thick ice could've provided
a route to shore,

But one piece of evidence
suggests the windiate crew

Did not simply walk
off the ship.

Clarke: Now, the lifeboat
has been left behind.

Knowing that the ice is
sometimes treacherous,

You would've expected them
to have possibly taken

The lifeboat with them.

Wade: And the latest analysis
of wind directions suggest

That a significant lake freeze
didn't happen in this period.

So getting stuck seems unlikely,
and even if that did happen,

The force of ice crushing it
from all sides would be evident

On the windiate's remains,
which are undamaged.

But could a much more recent
tragedy on the high seas

Provide a new lead in
solving this puzzling mystery?

2017, the bering sea
in the northern pacific ocean.

Seattle-based crab boat,
the destination,

Sails into severely cold
and rough conditions.

Wright: They didn't even have
time to react

Before the vessel
capsized and sank.

Six people were killed.

Wade: A key cause of the sinking
was found

To be a buildup of ice
on the boat.

In very cold conditions,
when you have waves

And you have spray,

This spray will turn
into ice droplets

And start to
cover things with ice.

It just builds up layer
after layer,

Wave after wave
comes crashing in,

Until it reaches a point where
it just overtakes the vessel.

Wade: So, could a buildup
of spray ice

Have sunk the windiate?

Wade:
The 19th-century schooner,

The cornelia b. Windiate,

Is found undamaged
on the bottom of lake huron.

Could ice buildup,
the phenomenon

That sank an alaskan
fishing vessel, be to blame?

Wright:
It's the same deadly phenomenon

That they were caught
with sea-spray icing so quickly

And so perilously
that they sank

And didn't even
have time to react.

Wade: The windiate
was a sizeable vessel,

Capable of carrying large
quantities of heavy cargo,

So could ice really
have taken her down?

With the weight of ice
on the top of the vessel,

Rather than at the bottom
of the vessel,

You have these huge issues
with weight distribution.

And when the vessel goes over,

There's no righting moment
from the bottom of the vessel

To stop that ice
from pulling down.

Gravity is actually working
against the vessel.

Wade: And in the fresh waters
of the great lakes,

Another factor would've been
working against the windiate.

Ortiz-vazquez: Fresh water would
freeze quicker than salt water.

There is a possibility of having
that ice buildup

Just from the wind.

Wade: Experts have calculated

That the rate of freshwater
ice buildup

On the day
of the windiate's sinking

Could've reached as much
as 16 tons per hour.

Polakowski: The only kind of
defenses that crews have

Is going out and actually
breaking it off by hand

Using hammers, wedges,

Anything they have
to kind of beat back the ice

And outrun mother nature itself.

Wade: And spray ice on the decks
may account for another element

In the windiate mystery...

The missing crew.

You're on a moving ship.

The crew would've been
sliding across it.

Clarke: Meaning that they were
actually washed off the ship.

The spray, which was adding ice
to the ship,

Actually got rid of them.

Wade: Whether or not the ice
sent the crew sliding

To their deaths,

It may have played
an even more surprising role.

It could be responsible for
the remarkable preservation

Of the windiate wreck.

Clarke: So when it's covered
with the ice,

That adds enough weight
to sink it,

But the ice, of course,
is also slightly buoyant,

So that is why she ends up

Having a nice, smooth glide
to the bottom of the seabed.

In fact, she might've even sat
there suspended in the water

For a bit.

Ortiz-vazquez: The ice just
melts away and, boom,

You have your perfect ship
at the bottom of a lake bed.

Wade: And this is how she was
found over 100 years later.

But there's no way of knowing
for sure that ice

Was what sank the ship.

The trouble is, they'll be
nothing for us to discover

That proves the ice
because the ice, of course,

Is mostly made up of the water

Which has existed
around the windiate now

For hundreds of years,
so it's a theory.

Further examination
of the windiate may, in time,

Offer up other answers.

For now, we're left with just
the scene of the crime.

The prime suspect
has melted away.

♪

The history of naval warfare is
a record of winners and losers,

But do historians ever record
the wrong result?

A recent underwater discovery
in the mediterranean sea

Suggests just that.

Could it lead to a radical
reinterpretation of the history

Of the ancient world?

♪

In 2002, a fisherman trawling
off the western coast of sicily

In the mediterranean sea

Is astonished to pull up
not a fish,

But an artifact
from another world.

A massive, solid cast piece
of bronze.

Wade:
Stunned marine archaeologists

Recognize the mystery item

As something that's never
been found

In the ocean before --

A battering ram
from an ancient warship

More than 2,000 years old.

The bronze battering ram
at the front of these ships

Was the height of technology
of its period.

It was the tomahawk
crew's missile,

The trident ballistic missile
of its period.

We're talking something
which could weigh,

In itself, up to a ton.

Wade: Ancient battering rams
were designed

To inflict the maximum amount
of damage to enemy vessels.

These rams are built with kind
of three fins that angle out.

These fins are meant to spring
the planks of the enemy ship

And tear them at the seams,

So that the rest of the ship
kind of becomes undone,

Almost like a zipper.

It's the tip of a spear
magnified a million times,

And, you know,
you have all that weight,

All that speed,
all that pressure.

Pretty irresistible force.

It's like nothing else that has
been found in antiquity.

Wade: The dramatic discovery

Prompts a major
archaeological survey.

What they discover
is extraordinary,

A site spread over an area
the size of manhattan,

And within it, the remnants

Of one of the most important
naval battles of antiquity,

The battle of the aegates,
also known as egadi.

The battle of egadi
was between the romans

And the carthaginians.

Elliott:
The romans, at the time,

Are expanding their sphere
of influence throughout Italy.

They've found that they were
confronting the major

Local power,
the carthaginians.

Goodman:
This battle is considered

A really critical moment
in military naval history

Because the romans weren't
really known for winning at sea.

Wade: But according to all
written records from the period,

The romans were victorious.

The battle of egadi basically
put the roman republic

On the map.

Polakowski:
This is a big pivotal moment,

Where rome finally goes
from a regional power

To kind of a mediterranean
maritime power.

Wade: The traditional
interpretation of the result

And importance
of the battle of egadi

Has been accepted
for over 2,000 years.

But when they study
the battle site,

Marine archaeologists
find evidence

That suggest
a very different story.

The battering ram,

The exceptional item first
recovered from the egadi site,

Turns out not to be
the only one.

Goodman: This is a really unique
site in the sense

That multiple battling rams
have been found.

Wade: Until now,
only three of these rams

Were known to be in existence
anywhere in the world,

And none were found
where they fell.

But as marine archaeologists
comb the egadi site,

They are amazed to discover

More than 20
of these ancient weapons.

Battering rams would've
been used by both sides

In the battle of egadi

But with different features
and designs.

The unique type of alloy
and the quality of these rams,

You can pinpoint
which ones are roman.

Wade: The number of rams found
on the seafloor

Gives an indication
of the number of ships

That were sunk in the battle,

But remarkably,
when archaeologists do the math,

They can confirm that only one
of the rams comes from carthage,

But a staggering 15 are roman.

How are these roman rams
are the bottom of the sea?

Wade: Instead of being,
as history tells us,

The naval victory
that founded an empire,

Did the romans in fact
lose the battle of egadi?

♪

History has recorded a great
victory for the romans

At the naval battle of egadi,

But recent finds
in the seas of sicily

Suggest something
very different.

Goodman:
When we find something

That doesn't fit
our expectations,

Maybe some of our theories
are incorrect,

Maybe we need to reconsider
how we understand that time

Or that battle.

Wade: In this period, despite
being a great force on land,

The romans scored
few victories at sea.

Goodman: This is something that
the romans were not considered

To be the experts at this,
and so during this battle,

The advantage was not
on the roman side.

Wade: The carthaginians had
an unrivaled reputation

As master mariners
and naval tacticians.

And in the battle of egadi,

The roman force was less
than half the size

Of the carthaginian fleet
of up to 700 ships.

The underdog in this fight
is the romans.

They have been the losers
at just about every battle

With the carthaginians
up to this point.

Wade: So did the romans in fact
lose as suggested

By the number of rams
discovered on the seafloor?

Or could there be another reason
why the remains

Of so many roman ships
were found at the egadi site?

Elliott: Building a warship
is very expensive.

Therefore you go to
every measure to make it

As cost effective as possible,

And the easiest way to do that
is to use a captured ship.

Polakowski:
A lot of the roman ships

That we're finding here
at this battle

Are actually reused ships that
were captured

About nine years previous
at another naval battle,

Where the carthaginian side
was actually victorious.

Wade: Capturing ships

And putting them
to work in your own fleet

Is a tactic that's been employed
by navies

Throughout the centuries.

The british navy, for example,
captured many french ships

And used them afterwards
as part of their own fleet.

Wade:
The theory that carthage

Was using
captured roman vessels at egadi

Would explain why so many
roman rams have been found,

And it tallies with
the historical account

Of a roman victory,

But with much of the egadi site
still to be excavated,

A definitive answer
could be years away.

Every year that we go back,
every time that we actually

Do surveys there
and find new things,

The questions just get
exponentially bigger.

With new technology, we're
uncovering more and more wrecks

From further
and further back in time.

I wonder what rereadings of
history remain to be discovered?

♪

The dark, frigid,
lifeless ocean depths

Have often been considered
a good place

To hide our unwanted secrets,

But a danger hidden
is rarely a danger resolved.

Such is the case with
the 75-year-old mystery

Of the toxic nazi submarine.

February 1945,

The closing months
of world war ii.

With defeat in europe looming,
hitler orders

One of nazi germany's fleet
of long-range u-boats

To carry out a top-secret
underwater mission.

Elliott: This is the end
of the second world war,

But the germans are beginning
to transport

Some of their secrets
from the third reich.

The hope being that some
of its leading-edge,

Cutting-edge key nazi secrets

Can find a way to be used
from a new home in japan.

Wade: The nazi goal is to help
the japanese

Change the course of the war
in the pacific.

Tuttle:
If the sub got to japan,

It would have given
japan technology

That may have helped them
resist the americans.

Wade: The operation requires
the utmost secrecy.

If you have something that you
really want to keep well hidden,

A submarine was an ideal
form of transportation.

Wade:
What the germans don't know

Is that british codebreakers
at their bletchley park hq

Have cracked
the nazi's enigma code.

Hitler's top-secret mission
is no longer a secret.

From the allies' point of view,

They didn't know exactly
what was on the submarine,

But it was absolutely critical
they find it and destroy it.

Rondeau: They intercepted
these communications,

Which indicated to them that
this had potential implications

For the outcome of the war.

Wade: And the british have
another key advantage.

One of the german
submarines' engines is faulty,

And it's emitting a noise
that can be tracked.

And there's this cat-and-mouse
chase up the norwegian coast.

Wade:
Like hunting down wounded prey,

British submarine, hms venturer,
stalks u-864

Through the freezing,
murky depths of the north sea.

Venturer is finally at a point
where it has no choice.

It's afraid that it's going
to lose the 864.

Wade: So the british sub quickly
launches four torpedoes.

It's easy to sink a ship
on the surface.

For a submarine to sink
another submarine is unheard of.

Wade:
The first three torpedoes miss,

But the fourth finds its target.

A massive explosion rips
through the midsection

Of the german u-boat.

This is the only time in history
a submarine submerged,

Using a torpedo,
has sunk another submarine.

Tuttle: The captain of the ship
would say probably "skill,"

About 90% of the rest
of the world would say,

"heck, that's a lot of luck."

Wade:
U-864 sinks in 500 feet of water

With all 73 crew on board.

For the british navy,
it's job done,

But the norwegians,

In whose waters the wreck
of the german sub lies,

It's a different story.

Because of the materials
that were known to be aboard,

It was
secret military materials,

It was always a priority
to try and find her.

Wade: She's finally found
after 70 years,

But there's a problem.

There are over 1,800 canisters
full of liquid mercury.

Wade: The nazi sub is toxic.

When german u-boat 864 sinks

In the closing stages
of world war ii,

She remains hidden
in the darkest depths

Of norway's north sea
for over 70 years.

It's not until 2003 that
the wreck is discovered.

Elliott:
A norwegian navy minesweeper

Using unmanned
underwater vehicles

Discover the submarine
on the seabed,

And it found the submarine
was in two major portions

With a spread
of debris around it.

Wade:
Is the sunken nazi u-boat

Finally ready to give up
her wartime secrets?

The difficulties of doing
recoveries on a military site,

The obvious one is,

Well, this is
a german submarine at war.

How many torpedoes
are still left in the vessel?

Wade:
U-864 is thought to contain

Over 20
high-explosive torpedoes,

But there's something
even more dangerous

Waiting on the underwater wreck.

By 2003, norway is in possession
of the original 1945 manifest

For the nazi sub's final voyage,

And it reveals a particularly
sinister cargo --

Mercury...

1,857 canisters,

Which equates to over 65 tons,
enough poisonous liquid metal

To cause
an environmental catastrophe,

And once in the food chain,
a serious danger to human life.

Mercury is a neurotoxin.

It's bad for the brain,
for your neural system.

It can cause dizziness,

Loss of function
in your muscles,

You can't walk, you can't talk,
slurs your speech.

Wade: Before they can
even think about

Recovering this lethal liquid,

Scientists face a more
immediate challenge.

A major problem with the project

Is that the submarine is lying
on the bottom of a shelf,

So it's sloping off
into the deep atlantic.

Part of the submarine
could actually slide

To a deeper depth.

Wade: If the u-boat slips,

It could release all the toxic
mercury into the sea,

Potentially poisoning
an entire ecosystem.

And it's not stable.

At any time,
it can kind of fall apart.

Something has to be done.

Elliott:
So the key thing to start with

Is to actually stabilize
the submarine.

So a platform, a shelf, is being
built underneath the submarine.

Wade: The operation is
further complicated

By the depth of the wreck.

At over 500 feet down,
it's too deep to send divers,

So a brand-new remote system

Is designed to stabilize
the sub using gravel ballast.

It's not like you can just take
a big shipload of gravel

And just dump it off
the side of the ship.

It has to strategically
be placed using technology.

An r.O.V. Basically is almost
sort of like a garden hose

In that
it's spraying small gravel,

Or very coarse sand,
to stabilize the wreck.

Wade: The stabilization of u-864
is successful,

But despite this,
there are indications

That the mercury
may be spreading.

We are detecting leaks
of this mercury right now.

How much has already leaked out?

How much is safely contained?

The recovery process itself

Might actually spread
the mercury around.

You might disrupt the canisters.
You might break them.

So it's a catch-22,
if you do, you could be damned,

If you don't,
you could be damned.

Wade: But the salvage team think
something even more deadly

May be on board.

So the speculation at the time
was is that the u-864

Could have been carrying
enriched uranium.

Wade: Enriched uranium

Is the vital element
in nuclear bombs.

Thankfully, testing around u-864
does not show traces of uranium,

But it's another threat
that must be considered

By the salvage team.

With the toxic danger
of the wreck

Thought to be too great

To attempt to raise it
to the surface,

Other options
are being considered.

Another way that norwegians
are looking at

Is to cover it
in a sarcophagus.

I want to say a post-chernobyl
approach.

Encapsulate it in, you know,
a giant concrete cap.

Wade: One plan proposes

That the toxic submarine
be given an underwater burial

Beneath 40 feet
of concrete and gravel,

But locals are concerned

That the mercury
will still pose a threat.

So the solution
to a toxic problem

Created by allied action
at the end of world war ii

Remains elusive.

The mystery for us here
is we still don't know

Exactly what we're dealing with
within the submarine,

And once we do know,
what to do with it.

There have been rumors
over the years

That in addition
to its toxic cargo,

U-864 may have been carrying
nazi gold,

Or even the last will
and testament of adolf hitler.

But until we find a way
of accessing the wreck safely,

All of this will remain
a tantalizing mystery.