Original subtitles

Wade: What was responsible for the loss of

a nasa space capsule deep in the mid-atlantic?

It's not losing a needle in the haystack.

It's like losing the head of the needle in the haystack.

Wade: What is the underwater secret

behind ship disappearances in the devil's sea?

Clarke: It is the bermuda triangle of the pacific,

and, in many ways, it is just as deadly.

Wade: And is a ticking time bomb at the bottom

of the baltic sea about to go off?

One can only imagine how horrifying that would be

to be confronted with the spectacle of

your impending doom.

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.

[ sonar pinging ]

♪

at the dawn of the space race,

a pioneering sub-orbital flight is about to put the usa

in pole position,

[ man over radio ] boy that's some sight.

But things go horribly wrong when

the capsule splashes down into the atlantic.

American dreams, along with years of research

and development,

sink to the ocean floor.

Exactly what happened on that fateful day remains a mystery.

But can a fresh investigation by an amateur sleuth

succeed where officials have failed

and finally reveal the answer?

July 21, 1961.

Returning to earth after his pioneering

sub-orbital flight, commander gus grissom

splashes down into the atlantic ocean

in the liberty bell 7 capsule.

A recovery helicopter arrives to secure

the capsule and take it back to base.

But suddenly, without warning, the spacecraft's emergency hatch

blows off,

leaving a gaping hole in its side.

Gus grissom is in the capsule, and water's now flooding in.

Wade: The astronaut hauls himself out through

the narrow hatch and into the sea,

but his ordeal is only just beginning.

The man's in outer space one minute,

and the next minute, he's on the surface of the earth,

and this is where he has the highest possibility of dying.

Wade: The retrieval helicopter focuses on the capsule,

but it struggles to maintain control.

Liberty bell 7 is taking on water and getting heavier

by the second.

The helicopter is dragged downwards.

Inside, emergency lights come on.

The engine is close to failing.

As the chopper's propeller creates

a churning wash of air and water,

grissom, beneath, struggles to stay afloat.

And there's, you know, all this prop wash coming down on gus.

They're not paying any attention to him.

They're concentrating on getting the spacecraft.

He's in his spacesuit, in his spacesuit

starts filling up with water.

He's taking on water,

and he's losing buoyancy.

Wade: With the capsule now weighing 1,000 pounds more

than the retrieval helicopter can handle,

the pilot is forced to make a tough, split-second decision.

He cuts the cord.

Liberty bell 7 sinks to the bottom of the ocean.

Nearby, gus grissom is facing a similar fate.

He's fighting to keep his nose above the water,

literally, until the backup recovery helicopter

comes in.

And then there is the iconic picture that

everybody remembers

about liberty bell 7 of gus like a dead fish

being hauled up into the backup recovery helicopter.

Wade: Why the mission goes so badly wrong

is one of nasa's greatest unsolved mysteries,

and, for some, a blemish on its reputation.

Rondeau: To lose liberty bell 7 in the moment was horrible.

It represented

the high point of nasa's space program.

It was an emblem of america itself.

So to have it in one's grasp

and to lose it,

it was seen as a real loss

of pride in the american space program.

Wade: The public want answers.

What went wrong, and who was to blame?

With the physical evidence lost deep under the atlantic,

people look to grissom for answers,

but the astronaut can shed little light

on those fateful moments.

Wade: Nasa's initial investigation finds no fault

in grissom's actions, but some are skeptical.

Clarke: Pilot error is, of course, a potential.

There's always the potential.

It's very easy to blame the organic matter in the cockpit.

Wade: Gus grissom's reputation as a flyer with

the right stuff is called into question.

An astronaut hero falls to earth.

Grissom's mission was part of project mercury,

the united states' manned spaceflight program.

The space race with the soviet union is in full flow.

Expectations are great, and the stakes are high.

Rockets are exploding left and right,

and these guys have to figure out how to

fix them and ride them and not get killed.

Wade: The race to the moon is on,

so every mission needs to drive progress.

Grissom's flight tests several innovations,

including, significantly,

a quick-release emergency hatch.

The hatch is sealed with 70 titanium bolts

embedded in an enclosed explosive casing.

A push button plunger detonates

the charge and releases the hatch.

For safety reasons,

detonation is a multi-step process.

The hatch must first be armed before pressure

is applied to the plunger to detonate the charge.

Although grissom's memory of the splashdown disaster

is hazy,

there is one thing he remembers with clarity.

Grissom claims that he armed

the explosive bolts but that he didn't, in fact,

detonate them.

Wade: But not everybody is convinced.

There are rumors immediately after this happened

that grissom panicked

and that he prematurely detonated the hatch.

Wade: Later, astronauts who detonate the plunger

suffer bruises -- one even suffers a laceration.

Grissom didn't have those bruises.

Wade: But the damage to grissom's reputation is done.

Grissom was victimized because of the loss of

liberty bell 7 and was really almost shamed

as a result of it,

and he really never recovered from that.

And it was the defining moment of his -- of his career,

to lose that spacecraft really hurt.

He was dogged for the rest of his life

over what he referred to as the "hatch crap."

wade: In 1967, gus grissom is killed

in the apollo 1 launch fire

with the mystery of what happened

in the liberty bell capsule still unsolved.

It's now 1999.

Salvage expert curt newport is armed with

cutting-edge technology

and an unerring desire to find liberty bell 7

and bring her home.

The mission to recover liberty bell 7 brought together

the best marine recovery people in the world

at the time.

Leopold: Newport gets all of the tracking data,

all of the telemetry he can find about

the flight of liberty bell 7,

and he begins to sort of zero in on an area where he thinks

it might be.

Wade: Operating at depths of up to three miles,

the team's submersible uses sonar to locate objects

on the seabed,

but can it spot a nine-foot-high capsule in a search area

which covers 24 square miles?

Tuttle: These capsules are unbelievably tiny.

To lose a space capsule in the middle of the ocean,

it's not losing a needle in the haystack.

It's like losing the head of the needle in the haystack.

Leopold: But they're very systematic.

They call it mowing the lawn.

Go back and forth in grids,

and you look for your best possible targets.

And he decides to start with target 71.

The controllers send their submersible towards it.

They point their video cameras at it.

Curt says, "that thing's got some height to it."

and as they slowly move in through the darkness,

the words united states appear on the side of this object.

I don't believe it.

And he has found liberty bell 7 after 38 years.

But will the capsule provide the key to

the mystery of what happened and restore the reputation

of astronaut gus grissom?

[ sonar pinging ]

[ sonar pinging ]

the loss of the liberty bell 7 capsule deals

a severe blow

to the american space program and leaves her commander's

reputation in tatters.

Finally, in 1999, the lost capsule

is raised from the ocean floor.

But can she help solve the mystery of what went wrong?

Goodman: It was an opportunity to finally look at

the physical hard evidence

of the condition of the capsule and to understand

what happened.

Wade: However, crucially, the hatch door is not found,

and despite extensive investigation,

the capsule does not provide definitive answers to the many

questions that remain.

The investigations are wound up,

but some people are still determined to find answers.

Years pass before nasa agrees to open up

its archive to writer and grissom biographer,

george leopold.

They think that the loss of liberty bell 7

is -- is probably one of the great mysteries.

Wade: With the passage of time,

he's hoping that a cold, objective eye

will unearth some fresh clues.

One piece of eyewitness testimony stands out.

Lieutenant john reinhart, one of the retrieval team,

is first on the scene.

His job is to remove the capsule's antenna

before attaching the winch hook from the helicopter.

He was in the helicopter opening with a hook

and a snipper,

and he said that when he touched

this ungrounded spacecraft,

he saw an arc.

Wade: A powerful electrostatic discharge.

Leopold: You've got a helicopter hovering over a spacecraft

and this vortex that's got a lot of energy in it,

and the metal touches metal, some of that energy is probably

gonna get transferred,

and that's what john reinhart thought he saw.

He was the closest person to the spacecraft when he sees

this arc,

and at that moment, the hatch blows.

So that leaves us with, you know,

the possibility that maybe it was the electrostatic discharge

that blew the hatch.

Wade: Upon further investigation,

leopold learns that in sea helicopter rescues,

static electricity discharge is a common phenomenon between

surface water and hoisting devices.

What's more, he finds evidence that nasa was aware of this.

The procedure that the coastguard of the u.S. Navy

uses is that you would never touch something

in the water with a helicopter over it until it's grounded.

Wade: Over the years, other theories have been put forward

for the premature detonation of the liberty bell 7's

hatch bolts

and the subsequent loss of the capsule,

but nasa didn't reach a definitive conclusion.

Leopold: They were in a hurry, they wanted to get on

to the next flight,

so they basically reproduce as many scenarios as they could

think of, and then they moved on.

So in the end,

you really don't know exactly what happened.

Wade: But with the final piece of evidence,

the hatch door itself, still under the sea,

the mystery endures.

But one thing seems clear -- with what we now know,

surely it's safe to conclude that astronaut

gus grissom had the right stuff all along.

♪

♪

conflicts fought out on our seas leave behind

a potentially lethal legacy,

discarded mines and all kinds of other dumped hardware

and unexploded ordinance often hidden deep beneath the waves.

Can new technology find a way of locating

and defusing this underwater time bomb before it's too late?

2005, the baltic sea.

A dutch fishing vessel is trawling

the relatively shallow waters of this semi-enclosed,

brackish body of water between scandinavia and europe.

They're basically scouring the sea floor, and they're

pulling up -- in addition to fish,

they're also pulling up anything that's on the sea floor.

Wade: The trawler's crew are hauling in their catch

when they notice something strange in the nets.

Their nets were arrayed on the seabed,

catching fish as normal, but they caught something

very unusual.

Wade: The details of what happens in the next few minutes

remain unknown,

but the conclusion is clear.

An explosion rips through the boat, killing three men.

Elsewhere on the baltic coast,

beachcombers find what they think

are pieces of amber in the sand.

They're picking them up and putting them in their pockets,

and the heat of their body is warming these up,

and it's causing people to have very serious

chemical burns.

Wade: Around the same time, scientists studying fish in

the baltic find some specimens containing cancerous tumors.

Multiple mysterious incidents in the same

body of water are cause for alarm.

But are they linked,

and if so, what's going on under

the cold surface of the baltic sea?

Surrounded by nine different countries

and a historical boundary between east

and west europe, the baltic sea has been

the front line in conflicts

from the crimean to the cold war.

But it was world war ii that really set fire to this region.

Clarke: There was a nonstop mine warfare going on.

Millions of mines were laid in these waters.

Wade: But they were not the only munitions

dropped into the baltic.

At the end of the war,

an estimated 300,000 tons of ordnance -- bombs,

shells, and ammunition -- were dumped into the depths.

Rondeau: The immensity is --

is really unthinkable -- we don't have accurate maps

as to where this was dumped or by who,

so, really, it's anybody's guess

as to the extent of this problem.

Wade: Now,

75 years later, this explosive underwater legacy is thought to

be responsible for dozens of deaths and serious injuries

every year.

And new evidence reveals that there's an even

greater danger at the bottom of the baltic.

[ sonar pinging ]

[ sonar pinging ]

hidden in the depths of the baltic sea are

hundreds of thousands of tons of world war ii munitions

with a combined explosive force capable,

it is estimated, of flattening a city.

We know these ticking time bombs are there on the seabed.

Rondeau: There's a high risk of fishermen bringing

up this unexploded ordnance from the sea floor.

Wade: This, it turns out, is exactly what

the unlucky dutch crew hauled up in their nets.

One can only imagine how horrifying that would be

to be confronted with the spectacle of

your impending doom.

Wade: But in addition to this obvious, volatile danger,

there's something more insidious going on.

Some describe these unexploded ordinances,

or uxos, as weapons that wait.

Figueroa: In the ocean,

these metal canisters can degrade over time.

That leads to the potential for toxic materials

to leak into the environment.

Wade: The beachcombers who suffered serious burns

unwittingly picked up

pieces of phosphorous used in incendiary devices.

And the baltic marine life displaying abnormalities

tested positive for the chemical compound, tnt.

Elliot: Tnt is one the most common explosives used in

the world today and certainly was used in the 20th century

in the context of the first world war

and the second world war

wade: As well as being highly explosive,

tnt is poisonous.

Figueroa: It's toxic to life -- it can cause cancer.

It can bioaccumulate in the environment,

meaning small organisms take it in,

larger organisms eat those.

Clarke: These materials can then be transmitted up

the food chain to the animals above them.

And so this is how it's ending up in fish.

We're talking about the potential

for a biological catastrophe.

The massive quantities of world war ii munitions

hidden on the bottom

of the baltic sea now pose a multifaceted threat.

The extent of the problem is phenomenal.

Wait, where is this stuff?

It's everywhere, but nowhere.

Goodman: How do we find them?

How do we neutralize them?

How do we keep them from

causing any kind of environmental damage?

Wade: Specialist divers are normally at

the heart of such cleanup operations.

They're bomb disposal experts, but they're also divers.

They combine these two very, very high skillsets.

Wade: Their work is complex and hazardous.

The traditional method was that once a mine was found,

it would either be hoisted aboard a ship

if it was considered safe and disarmed on the ship,

or it would be disarmed in the water.

Rondeau: That's very complicated.

It's very expensive.

It's also very dangerous.

Wade: Over the years, dozens of military divers

have bean killed in mine clearing operations.

So a different approach is needed.

Operation open spirit is an international

maritime mission to clear the baltic

led by the navies of lithuania, latvia, and estonia.

It's using the latest technology like the remus

autonomous underwater vehicle,

specially developed to search out mines.

The remus 600 is one of the most advanced of

the auvs available.

It has great imaging sort of equipment.

It has great sensory equipment to find mines,

and it's very, very moveable.

But what they do mainly is they keep divers out of the water.

Wade: The self-piloting mini submarine

uses sonar to locate mines.

They can literally survey miles and miles

of seabed per day.

Wade: Once a mine is found, the remus auv

can destroy it using a directed explosive charge.

It's a significant advance on using divers,

but with hundreds of thousands of pieces

of dangerous munitions on the sea floor,

even with the latest tech, this deadly task

could take years.

[ sonar pinging ]

[ sonar pinging ]

wade: The latest underwater technology is being used

to find and destroy

world war ii weaponry on the baltic sea floor.

This painstaking process could take years,

but recently, a team of scientists at keele university

in germany has made a remarkable breakthrough.

They have come up with an ingenious way of neutralizing

tnt, the most abundant explosive in the baltic

and one that is starting to poison the environment

by employing the services of

a mysterious microscopic organism.

There are microorganisms that

can take energy or metabolize tnt.

They exist, scientists have found them.

Wade: The bacteria essentially consume the tnt,

breaking it down into its component elements.

We call it biotransformation, because it's taking

energy and it's transforming it into something else.

Basically, the idea is that you enclose the munitions with

some sort of membrane

that has this bacteria, and the bacteria will transform

the tnt into nontoxic materials.

Wade: So far, the microorganism has only

been tried out in the laboratory.

How it will work in the sea itself is still unknown.

Figueroa: It's super hard, like, this is not easy science.

We have to redesign the experiment and figure out

what this looks like in the field.

There's a lot of unknowns, but the potential is there.

Introducing a new bacteria into the sea has risks.

So whether this turns out to be the silver bullet

for a dangerous wartime legacy

or another environmental time bomb,

we wait and see.

♪

♪

the reputation of history's most famous pirate,

blackbeard, has long been debated.

For some, he is a brilliant leader of man,

a generous captain who commanded great loyalty.

For others,

he's a ruthless brute who exploited his crew

and stole their share of the treasure.

Can the latest research into the wreck of his flagship shed

light on the mystery of the true character

of this ultimate pirate?

June 1718.

For months, blackbeard and his pirate fleet have been

terrorizing the caribbean

and the east coast of the american colonies.

With his famous flagship, the queen anne's revenge,

in need of maintenance,

blackbeard sails his flotilla north up the coast

from charleston in search of a place to lie low.

Elliot: Blackbeard had just mounted

a highly successful raid on charleston.

So his fleet, which includes the queen anne's revenge,

is fully loaded with all the things he's captured.

Polakowski: At the end of 18 months of raiding,

his ships are probably in need of repairs, refitting,

and they're looking for a place to, uh,

dock up their ships.

Wade: Led by the fleet's

smaller ships, the queen anne's revenge heads

for the secluded port of fish town.

The flotilla sails in through a series of

narrow channels known today as the beaufort inlet.

Blackbeard's fleet enters beaufort inlet,

and they're going at full speed, full sail.

Wade: As the pirates navigate the tight waterway,

something happens to blackbeard's flagship.

The 100-foot fighting ship crashes

at speed into a shallow sandbar.

The main mast cracks, and some of the ship's timbers rupture,

so from that point onwards on the sandbar,

the ship is not seaworthy, but it is still

fully laden with all his plunder.

Wade: The treasure on board is transferred

to smaller vessels in the pirate flotilla.

But there's no room for the majority of the crew,

so blackbeard selects a few essential personnel and leaves

the rest on a nearby island.

The basic facts of what happened to blackbeard's ship

and his crew have never been in dispute.

But the same can't be said of the pirate captain's motives.

There is no debate that what happened

is the queen anne's revenge runs aground.

The debate is on whether or not

it was intentional or whether it was unintentional.

Wade: So was this an accident?

Or part of a plan?

One rare eyewitness account strongly suggests

a pirate plot.

Elliot: David harriet is a guy who was captured by blackbeard

and later became a very important member of his crew.

He says that blackbeard deliberately ran

his ship aground, and this is in the historical record.

Wade: Putting his flagship out of action would have given

blackbeard the excuse to leave behind many of his crew.

But to what purpose?

Polakowski: In a pirate crew as in any crew,

there's shares that get divided up.

If a captain cuts his crew in half,

that all the sudden means more spoils for

the captain and the people that he chooses to share

the spoils with.

Wade: But what blackbeard gained in treasure,

he would surely lose by leaving behind his famous ship.

Or would he?

One thing to bear in mind here is that this ship was very,

very recognizable up and down the eastern seaboard of what is

now the united states

and the various navies, they were coming for him.

The question for blackbeard was always how long

would the queen anne's revenge continue to be an advantage?

How long before she attracted so much attention

that the royal navy

was forced to send out larger ships to fight him?

Wade: For almost 300 years,

blackbeard's flagship and the pirate captain's

true intentions are lost to history.

But then, in 1996,

underwater archeologists exploring the beaufort inlet

make an astounding discovery.

The queen anne's revenge was found.

The really interesting thing is what will this site tell us?

Will it really tell us what happened on that fateful day?

Did he mean to destroy his ship, or was it an accident?

[ sonar pinging ]

[ sonar pinging ]

wade: Did the notorious pirate, blackbeard,

deliberately run his ship aground

in a ruthless bid to

downsize his crew and make off with a larger share of the loot?

Off the coast of north carolina,

the scattered remains of the queen anne's revenge

could hold the answer.

The queen anne's revenge is the only pirate ship that

we've ever found that has been archaeologically identified

as a pirate ship.

Elliot: The site of the wreck has

been studied continuously since it was found,

and it turns out to be an absolutely extensive site.

It's absolutely huge.

Wade: The discovery of the ship's anchors proves

particularly significant and could help

unravel the mystery of what happened to

blackbeard's flagship.

One of the key things we're looking for is the positioning

of the anchors, where they used them

to try and pull the ship off, to try and pull the ship

away from the banks.

The largest anchor was found directly astern and in

a position where you could literally pull the ship

back on it.

Wade: The location of the anchors on the seabed

suggests that the sailors

mounted a complex mission to heave the queen anne's revenge

off the sandbar.

That does beg the question,

why did they take so much trouble to try

and get the ship hard aground off the sandbar?

Why would you do this

if you were actually purposely trying to destroy your ship.

Wade: And it's not just the anchors.

Experts think that the positioning of the ship's

heaviest cargo

is further evidence of an attempt to save

the stricken vessel.

The evidence on the sea floor shows that the crew might have

been actually moving the goods and cargo

and cannon within the boat to try to move the weight around

to refloat the queen anne's revenge.

Wade: If blackbeard was trying so hard to save his flagship,

surely he had no intention of running her aground.

But how else did she end up on the sandbar?

To my mind, what we have here

is an absolutely massive maritime screwup.

Clarke: You have to remember in this period,

they don't have the charts we have these days.

They don't have the understanding of the depths

and moving of sandbanks,

which we have regularly charted by

oceanographic vessels.

Polakowski: Sandbars in this area shift,

which means that depths change and that you really kind of

have to be on a constant, vigilant lookout.

More likely, he was navigating blind.

Wade: Unfamiliarity with the inlet's

dangerous shallows might not have been the only factor.

Blackbeard's flagship was also in poor condition.

The queen anne's revenge has been at sea for a year.

She's got a lot of barnacles on her.

This is not a ship you want to be

taking this close in shore at this speed.

Wade: If the running aground was accidental,

it's likely that the decision to maroon the crew wasn't

a selfish act but an unavoidable one.

He's faced with a situation where he knows

now he can't remove the ship from the sandbar.

He's also not got the space on

the sloops and brigs left to remove all

the crew from the queen anne's revenge.

Wade: Perhaps blackbeard had no choice,

but leaving the crew did mean keeping the gold.

The odds are it was unintentional,

but he certainly did turn it to his advantage.

Wade: It's a tantalizing theory,

but what other evidence could still be found?

For many, the site holds more secrets.

Clarke: Through modern archaeology,

the hope is we can find out the answers

to all these questions.

The hope is we can discover the information that's

necessary to tell us what happened

to the queen anne's revenge and what blackbeard was thinking

when his ship went down.

♪

fire-breathing sea dragons are the stuff of ancient legends,

but where do these myths originate?

Stories from an area of ocean south of japan renowned for

the disappearance of many ships

suggest a dramatic new interpretation of

this age-old mystery.

August 1944.

The philippine sea in the western pacific ocean.

A japanese fighter aircraft is

returning from a routine mission.

Rondeau: The japanese pilot saw what looked like

some sort of large dragon-like creature,

fire-breathing creature

swimming in the water.

Could there be some kind of sea dragon out there?

And could it be linked

to multiple ship disappearances?

[ sonar pinging ]

[ sonar pinging ]

an area of the western pacific known as the devil's sea

or dragon's triangle is

notorious for ship disappearances, and in 1944

an eyewitness account describes something strange in the water.

The pilot's official report describes a serpent-like

monster navigating through wildly churning waters

emitting huge flames.

It's a part of the ocean that we don't

have a clear understanding of what's going on there.

Wade: The extraordinary sighting takes place in

an infamous section of the pacific.

The devil's sea is located to the south of japan,

skirting the coast of taiwan and extending into

the philippine sea.

For 1,000 years,

it has been notorious.

This is an area where ships have gone missing for a very,

very long time.

Wade: The devil's sea has been swallowing ships

since at least the 13th century.

During the reign of kubla khan, who was the grandson of

genghis khan,

the chinese embarked on a period of exploration.

Kubla khan's navy was -- was lost in this area,

and potentially as many as 40,000 sailors drowned

as a result.

Wade: Across the region, scholars attempted to come up

with explanations for this unfathomable tragedy.

One of the founding theories

was that they were being swallowed by

a sea dragon,

and that's early chinese mythology, of course.

These ancient cultures, uh, when they see things,

you know, how do they explain them?

What is it?

It's a sea monster.

Wade: Over the centuries, the devil's sea's lethal

reputation has grown as

the number of ships that have been lost in its waters

has increased.

It is the bermuda triangle of the pacific,

and, in many ways, it is just as deadly.

Wade: Some cases have involved enormous vessels,

including the largest british ship ever lost at sea,

the mv derbyshire.

Wright: Huge ships like the derbyshire,

twice the size of the titanic, being lost...

How in the world is that possible

in any part of the world?

Wade: Many argue that high numbers of

disappearances simply reflect high volumes of traffic.

It's a very active part of the ocean.

There's a lot of transit that occurs in that particular part.

Wade: And when historic cases have been investigated,

the culprit for many vanished ships in the region turns out

to be one thing.

Rondeau: It's an area that's prone to typhoons,

and some shipwrecks are known to have been the victim of

severe typhoons.

Wade: But these tropical cyclones can't explain

away all the disappearances in the devil's sea.

In 1953, a japanese research vessel

is sent to study the area.

She's equipped with the latest in oceanic

surveillance technology,

and expectations are high that she might shed light on

the devil's sea phenomenon.

But she, too, vanishes.

I guess that's a little irony there.

It's sent out to look for lost ships...

Itself is lost.

Wade: The research ship disappears

in good weather conditions.

But a crew member on one of

the vessels sent to search for her reports

something remarkable.

He states that a section of sea in the area where

the research ship is thought to have vanished appeared to

boil and spew smoke.

An incident over 30 years later

and nearly 6,000 miles away off tahiti could hold the key to

this mystery.

The oceanographic research vessel, melville, is

studying atmospheric nuclear testing in the pacific.

The scientists on board have already

noted some unknown intermittent

underwater rumblings.

Then, all of a sudden, the ship starts to

shake violently.

The sea around the ship

becomes a boiling soup,

spitting and churning.

The crew are absolutely terrified.

Speculation is that what it may

have been observing was actually volcanic activity.

Elliot: They may have been floating above

the epicenter of a new volcano forming.

♪

wade: Miraculously,

the underwater volcano does not sink the melville,

and her crew live to tell the tale.

But could what they experienced shed light on some

of the mysterious ship disappearances elsewhere

in the pacific?

The devil's sea straddles four major tectonic plates

and, it turns out, is dotted with underwater volcanoes.

This entire region is part of the pacific rim of fire.

So there's this very active system that exists

right beneath the waters where these events occurred.

So in geologic terms, the edges of the devil's

triangle, at least the eastern edge of the devil's triangle,

is an area that is very seismically

and volcanically active.

Wade: So could underwater volcanoes be

the real phenomenon behind the sea dragon legend,

which started with the loss of kubla khan's navy

and which was still inspiring reports centuries later during

world war ii?

If you're a pilot, and you see an underwater volcano,

you might call it a fire-breathing dragon,

especially if lava is being spit into the air.

Wade: Underwater volcanoes could be the culprit,

but catching them in the act is an elusive science.

So whether subsea eruptions are a factor in all

the disappearances in the devil's sea

may never be known.

As more and more research is done in the coming years,

we will start to understand what is going on in that

particular part of the pacific.

In my experience, there is often a real phenomenon

behind even the most extraordinary legend

and maybe underwater volcanoes

do play a part in the sea dragon myth,

but there's rarely a single answer to a complex mystery.

So in the case of the devil's sea, we keep on looking.