Original subtitles

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.