All language subtitles for Mysteries.of.the.Deep.S01E06.US.Navy.vs.UFO.iNTERNAL.WEB.h264-ROBOTS_track3_eng

Wade: Can new discoveries
finally tell us

what led to one of the biggest
catastrophes on the great lakes,

the sinking
of the mighty ss fitzgerald?

The highest waves were up to 25
to 30 feet,

and that was exactly the place
where the fitzgerald was

and exactly the time
they were there.

Wade: Could newly declassified
information

explain a mysterious encounter
between the u.S. Navy

and an unidentified
underwater craft?

The science we have today
can't explain it.

It has me boggled.

Man:
That didn't just happen.

Wade: And what's making one of
egypt's top diving spots

one of the most deadly
in the world?

200 fatalities
for a single dive site

is very, very high.

This makes it only second to
everest in terms of the dangers.

♪

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

♪

I've been out on boats

that have suddenly become
caught in a storm.

There's nothing quite
as terrifying

as the destructive power
of wind, water and waves.

Sometimes, these forces
can prove too much

for even the strongest craft.

In 1975, a devastating maritime
disaster shocked the world,

and it still has experts
baffled to this day.

But could new hydrodynamic
research finally tell us

what happened
to the ss edmund fitzgerald?

November 9, 1975,

freight carrier,

the ss edmund fitzgerald,

sets off on her regular 5-day
journey across lake superior.

She's made more than 700
similar voyages

during her career.

The weather is calm in port,

but storm warnings
have been issued

for a section of the lake
along her route.

These were rough conditions
for smaller boats,

but for a ship
like the fitzgerald,

not something
that was overly concerning.

Wade: The ship's nickname
is the "mighty fitz."

at over 700 feet long,

she's a leviathan built to deal
with the roughest weather,

and she has an incredibly
experienced skipper at the helm.

Captain ernest mcsorley has
been navigating

the great lakes
for most of his life.

Tuttle: He is known for his
mastery of the lakes.

You don't become a captain of
the largest vessel on the lake

by not being a good captain.

He had a great reputation.

Wade: After 44 years on
the great lakes,

mcsorley is set to retire
in a few weeks' time.

Overnight, the fitz reports
increasingly stormy weather

to the coast guard.

Schwab: The waves were
increasing in height,

but the waves
usually didn't affect them.

Wade: Then, at 3:30 p.M.
On November 10,

the fitzgerald makes a call
to a ship

traveling a few miles behind.

Mcsorley reports that the fitz
has suffered some damage

and asks the other ship
to stay with them

until they reach the safety
of the nearest port.

He did make a request
that a ship would shadow him,

which basically means
that he was concerned that,

in case they did
have to leave the ship,

that there would be
another ship nearby.

Wade: The waves are now so high
they're interfering

with the fitz's
radar systems.

Mcsorley puts in another call
to the ship

that's following to ask
for radar plots

to help guide them into shore.

Goodman: It's clear from
the communications

that the captain was concerned.

I mean, it was a big storm.

They were taking on water,

but he also felt
that they could continue.

And he basically said
that things were going fine,

that she was moving
along like an old shoe.

But that was the last
that anyone heard from the ship.

Wade: At 7:15 p.M., just 17
miles from the safety of shore,

the fitzgerald disappears
from the other ship's radar.

They try to radio through
to the fitz, but she's gone.

♪

the only sign of the mighty
fitzgerald's existence

is two empty lifeboats.

There are no survivors
and no eyewitnesses.

What was it that caused
such a massive ship,

almost as long
as the titanic was,

to sink in a lake,
not in the ocean?

Goodman:
One of the big mysteries is,

why didn't the captain
send a distress call?

He would've known.
He had the experience.

He'd already reported that
they were bringing on water,

so it's really unusual

that there was
no additional distress call.

Wade:
What happened to the ss edmund
fitzgerald that fateful day?

It's a mystery that has haunted
the great lakes'

maritime community
for half a century.

[ thunder rumbles ]

lake superior is known

for its quick
and violent gale-force storms,

but captain mcsorley
had weathered

many of these in his time.

The event was incredibly quick

because between
the communications

and the loss of communications,

it was a very short period
of time.

There was no mayday
or sos call,

which is quite strange
from a boat there,

but it might have happened
so quickly

that nobody actually
was able to get to the radio.

Wade:
Crews are immediately scrambled
to look for the fitzgerald,

but hampered by bad weather,

it takes 4 days before the ship
is located using sonar.

She's resting on the lake bed
over 500 feet down.

It's a further 6 months
before remote underwater cameras

can be deployed
to take a proper look.

No one can believe
what they find.

Polakowski:
When they found the vessel,
it was split in two,

which means, usually, caused
by a catastrophic event.

Wade: It's unlike anything
they've seen before.

Rondeau: Initially, they thought
that they would find

the entire hull intact,

but researchers knew
that it had broken up.

The question is,
why did that happen?

Wade: For nearly half a century,
no one has known for sure

what caused this mighty titan

of the great lakes
to break in half,

but can new research
finally tell us

what happened
that fateful night?

♪

wade: In November 1975,

lake superior's
largest freighter,

the ss edmund fitzgerald,
vanishes with all her crew.

Those who find her wreck
are shocked by what they see.

From the remains
at the bottom of the lake,

it appears she's broken in two.

Now, more than 40 years later,

experts may be about
to solve the mystery

of what sank the fitzgerald.

Lake superior reaches depths
of over 1,300 feet,

but lurking just below
the surface are natural ridges

that are catastrophic for
any ship that comes too close.

There's a question of whether
the fitzgerald struck bottom

going over some of the shoals
near caribou island,

north of where it sank.

Wade: With his navigational
tools wiped out,

could the captain have smashed
his ship on the shoals?

I highly doubt a captain
of mcsorley's experience

would have issues
not knowing where shoals are.

Wade: The official investigation
blames

the ship's failed hatch covers.

The edmund fitzgerald had 26,000
tons of ore in it.

Therefore, she's going to be
low in the water,

and if you have waves
washing over the deck,

they should wash off.

If your hatch covers
aren't dogged down properly,

it's going to let water in.

Wade: But not all experts are
convinced by the hatch theory.

I don't really believe in that
because of the size of the ship.

You would have to leave them
open for quite a long time.

It would be gradual.

It would have to flood slowly,

and this was
a very sudden event.

Wade: What's more, the ship was
equipped with two powerful

7,000-gallon-per-minute
water pumps,

which were both running
at the time.

What it really looked like

was that there had been
a stress fracture

and that the ship
had broken in two,

and then both pieces spun away
from each other

and eventually sank.

Wade: Dave schwab was
a rookie scientist

working on the great lakes
when the fitz disappeared.

When the fitzgerald sank,
no one could understand

how there could be
a storm bad enough

to sink one of these
great lakes freighters.

They were designed to run
through the largest waves

they thought
they would encounter.

Wade:
But what if they came up against
the most unpredictable force

that mariners can face
during a storm --

rogue waves?

Schwab:
Rogue waves are mysterious.

Some oceanographers like to say
that it's a wave that's bigger

than 2 1/2 times the average
waves that are occurring.

Wade: Also known as freak
or killer waves,

rogue waves have been recorded
in the great lakes,

and they can be deadly.

Rondeau:
Rogue waves are an extremely
real thing on the great lakes

because the water
is not very deep.

A lot of people are surprised by
this because they would think,

"oh, well, you only get really
big waves in the ocean."

the thing that makes waves
in a lake body

particularly a problem
is that wave energy

has nowhere to go but up.

The great lakes are
really like inland seas,

but they have these sides.

So the effects of waves and the
way that waves can be produced

and produced quickly
is rather different.

You can get these very,
very large, very sudden waves.

It's sort of like a big bathtub.

And these waves can be changed
in their shape

by the surrounding topography.

So that means that if it's close
to the shore,

and there is a big wall,
it can bounce off

and just create a wave
with a different pattern

and make that wave grow higher.

Wade:
Lake superior is legendary
for a strange phenomenon

called the "three sisters."

rondeau:
There's an old saying with waves
that waves come in threes.

Oftentimes, the third wave
can be the biggest.

Goodman:
When you have rogue waves
that occur one after another

after another, the ship
doesn't have a chance to recover

after the first one
hitting the ship,

and this can cause it to sink.

Wade:
But how do we discover if rogue
waves appeared on lake superior

on that day more
than 40 years ago?

Oceanographer dave schwab
does what nobody

has ever done before.

He converts the records
of weather conditions

into a detailed
hour-by-hour model.

We could estimate based
on the output

from the meteorological model

what the wave conditions
were at any point in time

and any point in space
during those 3 days.

Wade: Schwab recreates wave
heights across the lake

for every hour during
the ship's tragic crossing.

We basically split the lake
into a number of grid boxes.

Each of those boxes that's
within the lake

is represented in the computer

as a cell that can interact
with wind from the surface

and with its adjacent cells.

Wade: Can this new mapping of
the water's dynamics

bring us a step closer
to understanding

what happened
that terrible night?

The wave model predicted that
the highest waves

were occurring
maybe up to 25 to 30 feet,

and that was exactly the place
where the fitzgerald was

and exactly the time
they were there.

Wade: And the model reveals
one other crucial clue.

As the waves were growing
in height,

the distance between them
was also growing.

Wave crests in the area

the fitzgerald sank were
becoming hundreds of feet apart.

Wade: The same length
as the ss edmund fitzgerald.

So one end of the ship
is on the crest of one wave.

The other end of the ship
is on the crest of another wave,

and there's nothing
in the middle

to hold that ship above water.

Ortiz-vazquez:
If this ship was so long that
it was actually riding two waves

at the same time,
and it was on each peak,

then the part of the middle
of the ship

would just be hanging in midair,

and that would create
a lot of stress on the hull.

And if you have very big cargo,
it could just split in half.

The distance between wave crests
becomes longer and longer.

During this storm, I don't know
whether that had some effect

on the dynamics
of the buoyancy of the ship

or how it reacted
to waves that long,

but these are unusually
long waves for the great lakes.

Dave schwab's work offers a new
and very plausible explanation

of the unique set
of circumstances

that could have caused
this terrible tragedy,

but until more evidence is
uncovered, it remains a theory.

And our deep waters often have
a way of swallowing

the evidence we need.

♪

we're used to stories of ufos
spotted in our skies,

mysterious visitors
from outer space,

but could there be alien craft
in our oceans?

In 2004, mysterious
underwater objects

are detected by u.S. Warships

on a training exercise
in the pacific.

It appears that no one knows
what they are.

Can newly declassified
information finally reveal

the secret of what's
going on beneath the surface?

November 14, navy carrier,
the uss nimitz,

is 100 miles off
the coast of san diego.

Reports come in of strange
unidentified objects

in the water.

Four f/a-18 hornets are sent
to investigate.

What they find astounds them.

The pilots observed an object
in the water

roughly the size of a 747,
basically right at the surface,

and the water around it seemed
to be boiling or churning.

For the navy to see an object
they don't recognize

is unbelievable,

but that it's acting this way
is even more mysterious.

Wade: Then the pilots spot
something totally incredible.

The pilots first observed
the bigger object in the water,

but then they subsequently see
a smaller object, about 40 foot,

come up to it, dock with it
and then take off into the air.

Wade: The smaller craft suddenly
starts to move erratically,

pinballing around.

The largest craft disappears
into the depths,

leaving no trace.

So here we have this
monster-sized

whatever thing bubbling
underwater and going away.

Wade: The smaller craft shoots
off through the sky

with the hornets giving chase.

They describe it as 40 feet long
and shaped like a giant tic tac.

It has no wings or visible
means of propulsion.

They're obviously tracking
a mysterious object.

Wade: And it does something else
that truly defies logic.

It plummets into the water
at incredible speed.

The calculations that they made
of the speed that this went

from about 20,000 feet
to the surface of the sea

was in about a second,
which is completely ridiculous.

Man:
That didn't just happen.

That's obviously traveling
faster than the speed of sound.

Where are the shock waves?

Where are the sound waves
that would emanate from it

and then the physical impact
of going from gas

to the other
medium, liquid,

without having some
kind of catastrophic failure?

Goodman:
What we're seeing doesn't seem
possible in terms of physics.

Wade: Missile cruiser,
the uss princeton,

is also taking part
in the exercise.

Her sonar picks up multiple
small objects

moving through the water.

The fact that these objects
are moving really,

really quickly
through the water,

we simply don't see this.

Wade: The fastest submarine
can reach a maximum speed

of 51 miles per hour,

but these objects are reported
to be traveling

10 times that speed,
over 500 miles per hour.

The science we have today
can't explain it.

Has me boggled.

Evidence of this encounter
remains classified

until the u.S. Military
finally releases it in 2017.

What are these incredible craft

that appear to defy
the laws of physics?

Is this proof of an underwater
alien encounter

or something else entirely?

♪

wade:
In 2017, the u.S. Navy releases
evidence of an encounter

with unidentified
submersible objects

traveling at extraordinary speed
through the pacific ocean.

No known craft can travel
that fast through water,

so what on earth could they be?

While we have planes that can
achieve supersonic speeds

through air,
water is 800 times more dense.

Polakowski:
When objects move through
an underwater environment,

there's a lot more friction
along the hulls of vessels,

so they have to produce
more power to be able

to push through whatever
they're trying to move through.

So in water,
there's more friction,

more barriers to push through,
versus than in the air.

Wade: The interaction between a
fluid and an object's surface

causes a phenomenon
called skin friction drag.

The faster you go,
the more power you need

at an exponentially
increasing rate.

So for something to be going
that fast through water,

it's got to be overcoming
this friction.

Mckay:
There are very real limits
to how fast you can travel

underwater,

and these objects
completely defy those limits.

Wade: Could they have come
from another world?

Mckay: The first thing that came
to my mind

is that this is a meteorite,

and if it were a meteorite,
you would see a burning rock.

And then you'd see
a gigantic splash

when it eventually
hit the ocean.

There's also the option
it's extraterrestrials,

which is beyond my knowledge

and beyond anyone's
if they're extraterrestrial.

Wade:
But there is one scientific
theory that might explain

how an object could move
through water at great speed

without the involvement
of extraterrestrial beings.

It's a technology
called supercavitation.

Clarke: This is where something
is working in an air bubble,

so instead of it having the
friction of water to deal with,

it's got the friction
of moving through an air bubble.

And the air around it is what's
interacting with the water,

so it's the friction of air
on water,

which, of course,
is very, very small.

So it manages to go
that much faster.

Wade: Over 20 years ago,

russian scientists developed
a supercavitating torpedo

said to travel six times
faster than its predecessors.

The russian shkval torpedo is
alleged to use supercavitation

to achieve unimaginable
high speeds,

but it's never been used
in combat.

So we're not really sure.

Wade:
New evidence is emerging

which suggests the russian
may not be the only ones

working on underwater
supercavitation technology.

Recently, the u.S. Navy

have filed for several
mysterious patents.

Mckay: Three of these patent
are suggestive

of a high-speed aerospace
underwater craft that could

potentially be capable
of these kinds of speeds.

I mean, the other question is,
is this patent really a patent

of something
that already exists,

or is this a patent
where this is the direction

that they're thinking in terms
of developing future technology?

Clarke: Is it something the
americans were developing

and then not admitting
that they had?

Is it something someone else
was developing?

We don't know, so that's
what the mystery is.

Wade: The nimitz sighting
happens in 2004.

The patents aren't lodged
until more than a decade later,

but could they
somehow be linked?

Supercavitation
has never been seen.

It's never really been
demonstrated,

and it's never been proven.

It is entirely a theory
which we're working towards,

so if it was something man-made,

then it is technology which is
yet to be admitted to the world.

Wade: But if this really is
top-secret technology,

why would the u.S. Military
release the footage

and publish the patents?

Mckay:
These sightings are so unusual,

and they defy physics
in so many ways.

And the fact that we know
about it, I think,

is highly unusual, as well.

Wade: There is one possibility
which could explain

the sudden release
of this information.

Clarke:
It could also be the u.S. Navy
putting a ruse out there

to wind up and make
the chinese and the russians

and everyone else
spend a lot of money

on something
which is impossible.

Mckay: Could this have been
a function of war games?

Could one side have been toying
with the other

with some new technology?

That potential exists.

Wade:
So are these extraordinary
sightings a glimpse

into our technological future

or evidence
of extraterrestrial life

or an exercise
in military deception?

The jury is still out.

♪

the ocean floor is littered
with shipwrecks,

possibly as many
as 3 million of them.

Many were sunk in battle
or wrecked by rocks,

and there are some ships
still intact on the seabed

that date back over 2,000 years.

So how could one disappear

from the bottom
of the ocean overnight?

Goodman:
Shipwrecks can't just disappear,

or can they?

♪

wade: I've witnessed up close
the sheer size

and bulk of some sunken vessels,

and for a huge shipwreck

to suddenly vanish from
the seabed seems impossible.

But is it?

Off the coast of borneo
are the wrecks

of three japanese cargo ships
which sank over 70 years ago.

Known as the usukan wrecks,

they become rich,
artificial reefs.

On January 31, 2017,

a team of divers
goes to see the wrecks,

but they've
completely disappeared.

These are documented wrecks
that have just gone missing.

Tuttle: People go back to look
for these wrecks.

They're gone.

There's a giant hole
in the seabed.

Wade:
Where these huge hulks once lay,
nothing but an eerie void

and a few mangled scraps
of metal remain.

You would expect pieces of it
to be left behind,

but to go to a known shipwreck

and to just see a depression
in the sediment there

and virtually nothing left
behind, that is bizarre.

Wade: Many wrecks do slowly
dissolve over time

due to saltwater corrosion,

but the usukan wrecks
disappeared much more suddenly.

How is that possible?

There are a number of theories
about what might have happened.

One of the possible reasons
that's been proposed is

that maybe it has to do
with commercial fishing.

For years, shipwrecks
have been disturbed

by commercial
fishing practices.

Wade: Could the vast net
of a deep-sea trawler

have caught on one of the wrecks

and dragged it
across the seabed?

There's no fishing boat
out there that's going to trawl

and move a huge battleship
on the ocean floor.

Wade: Our deep oceans also have
strong currents

running far
beneath the surface.

Cold temperatures
and high concentrations of salt

make them much denser
than the surrounding water.

Clarke:
We do know some currents

can carve deep forges
through the ocean,

can give really deep trenches.

Wade:
Ocean currents have been known

to move aircraft
debris large distances,

but we're talking about
three huge shipwrecks

weighing thousands of tons.

There is another force that lies
beneath our ocean bed

that could be powerful enough.

Elliott: The ocean floor
is very active geologically.

You only have to look at footage
of the deep ocean

to know there are very strange
things happening down there,

for example, vents giving off
tall columns of gases.

There are underwater
earthquakes and volcanoes.

We're just not normally
aware of them.

Elliott: We do have equipment
which monitors seismic activity

underwater around the world,

but that data doesn't show
any activity

which correlates to where
the ships are disappearing.

Wade: A deep-sea tremor of
the magnitude necessary

to swallow these ships

would surely have been
picked up by seismic monitoring,

and new evidence has come to
light that deepens the mystery.

The usukan wrecks are not
the only shipwrecks

to have gone missing
in recent years.

This has become
a widespread phenomenon.

Goodman: There's this really
unusual situation happening

right now where, worldwide,

shipwrecks are
seemingly disappearing.

Rondeau: Ships like hms warrior
in danish waters,

the hms repulse
and hms prince of wales

that were sunk in malaysia,

and the question is,
what's going on here?

♪

divers revisiting the site
of three sunken

japanese cargo ships
discover they vanished,

and other shipwrecks across
the world are going missing.

So what's going on?

Mckay:
The fact that it's happening
all over the world

in multiple locations

and in the numbers that we're
seeing, it's a catastrophe.

Wade: Perhaps there's a clue
in the type of ships

that are disappearing.

They have one thing in common.

They were all sunk
in world war ii,

and fragments left at some of
the sites give us further clues.

It appears that these wrecks
have been taken by human hands

in search of one
particular commodity.

Goodman: One of the reasons
that they were disappearing

is because of
the valuable metals

that are in these shipwrecks.

A shipwreck represents a literal
treasure trove of metals.

Brass, copper, there is tons
and tons and tons of metals

in these things.

Wade:
Under international law,

these shipwrecks
remain the property

of the country they came from.

In the case of the usukan
wrecks,

the government had permitted
a company

to do archaeological research,

but someone went a step further
and removed the wrecks entirely.

This is an example of what's
referred to as metal piracy.

These are people who are
illegally salvaging

these shipwrecks,
taking the metal, selling them,

I would presume,
in the black market.

Who are these metal pirates?

We don't know what nations
they normally come from,

what they're underground network
is like.

Wade: Many of these shipwrecks
contain something

that makes them
especially valuable.

World war ii ships are one
of the few remaining sources

of a particularly rare
category of metal.

This metal is highly valuable
because, for most of it,

it was produced before
the second world war,

so it has what's referred to
as the pre-nuclear signature.

We're talking about metal

that was produced
prior to nuclear testing.

Wade: Decades beneath the watery
depths

have protected the ships
from radiation,

which metal above the surface
has been exposed to.

They're called low-grade metals,

which means that they have
a lower radiation value,

and they're very useful
for medical use,

for technological use.

And it's also highly used in
modern scientific equipment,

so there's a big demand
for this kind of metal.

Wade: Metals with little or no
trace of radiation

are able to produce
more accurate readings

for finely tuned instruments

from geiger counters
to space sensors,

so they command
a very high price.

But the idea that these
historic sites

are being picked apart is,
for many people, abhorrent.

There are world war ii wrecks
with world war ii dead on them.

War vessels with war dead
on them

should be considered
war graves and sacred.

Goodman: We're talking about
places where people died.

We're talking about
military battles,

and they're essentially a place
that needs to be honored

and respected.

Wade: Can anything be done to
stop the illegal salvage

before all these irreplaceable
monuments are stolen?

Goodman: These are
well-organized professionals.

They have to have
the right equipment.

It's not cheap.
They're going out there.

They're using commercial diving.

Wade:
It's hard to police something
that's underwater

in vast areas of ocean,
but new satellite technology

could help the authorities
catch the pirates in the act.

Goodman: With all the satellites
that we have today,

if it's clear enough water
and shallow enough,

you can even see the shipwrecks
themselves from space.

They can actually monitor
subtle changes

that are happening
on the surface

where these shipwreck sites are

and be able to recognize
if something is happening.

When you try to move something
as large

as a shipwreck
from the seafloor,

you're undoubtedly going to
leave a large sediment plume,

and landsat can also be used
to detect these sediment plumes

to give some indication of
where wrecks are under threat.

These plumes would show
in discoloration

or differences in water,
and they could give us an idea

that the water
has been disturbed.

Wade: Satellites could provide
vital in helping us to monitor

these wrecks and to act quickly
if we spot anything suspicious.

Technology is really our way
to protect these wrecks.

It's important to remember
that these are cultural heritage

artifacts that need
to be preserved for everyone.

Wade: Will these technological
spies in the sky

be enough to turn the tide
on the mysterious metal pirates

before it's too late?

♪

I've been lucky enough
to explore

some amazing
underwater sites,

and among the most jaw-dropping
I've visited are blue holes.

Diving
these deep marine sinkholes

is like venturing
into an abyss.

But what has led to one
particular blue hole

being dubbed the most deadly
dive site in the world?

30 miles east of mount sinai

on the coast of
the egyptian red sea

lies a remarkable
underwater formation

known as
the blue hole of dahab.

The blue hole in dahab,
egypt, is this really,

really special place.

Wade: Dahab's blue hole
is a giant circular sinkhole,

a deep, vertical shaft
surrounded by coral and rock.

Its pristine waters
and proximity to the shore

have lured divers
to it for decades.

But despite its beauty, this
place holds a deadly mystery.

Clarke: The blue hole
of the red sea in egypt

is one of the world's
most mesmerizing

underwater phenomenon.

The trouble is it's also
a death trap.

Wade:
In August 2004, seasoned diver
andrey nikitin embarks on his

first dahab blue hole dive
with his buddy and their guide.

Knowing the challenges
of the site,

he has the right gear

and has even completed
several preparatory dives.

Despite all this,
he never makes it out alive.

Clarke:
This is an experienced diver.

He's well prepared.
He's organized.

It doesn't make sense.

Wade:
This isn't an isolated incident.

The dahab blue hole
is estimated

to have claimed the lives
of around 200 divers,

making it the world's
deadliest dive site.

200 fatalities
for a single dive site

is very, very high.

This makes the blue hole
only second to everest

in terms of the dangers.

It's very alarming for one spot,
for one popular diving spot.

Wade: Is there something lurking
at the bottom

of this underwater chasm

that's luring divers
down to their deaths?

Despite its beauty,
the blue hole is a place

that the local bedouin tribes
have long avoided

because, according to legend,
it's cursed.

There's a bedouin legend of
a young girl who drowned while

trying to escape
an arranged marriage,

and her spirit now haunts it.

This story indicates something
very strange

has been going on there
for some time.

Wade:
The curse of a bedouin bride,

or is there something
more tangible at work here?

♪

dahab's blue hole is the world's
most dangerous dive site.

The bedouin believe
it may be cursed

by the ghost of a local girl
who drowned there.

What is lurking in its depths

that has claimed
the lives of so many divers?

There are many unseen forces
in our oceans that can kill.

The red sea is home to more
than 40 types of shark,

including the tiger shark,

one of the few species
known to bite humans.

It also has deepwater currents

capable of pulling a diver
down in the depths,

but from the evidence so far,

it doesn't seem either of these
factors are responsible

for the deaths at dahab.

Could a new insight help us
to understand

what makes this beautiful
blue hole such a killer?

Figueroa: It's a deep dive.

You want to have training
and experience,

and it's a dive that you want
to have your wits about you.

Its deepest depth
is about 400 feet.

The maximum depth for
recreational divers is 130 feet.

Wade: Diving deep can come with
a dangerous side effect,

something known
as nitrogen narcosis.

Narcosis is having
a high amount of nitrogen

that accumulates in your body,

and that changes your perception
of what's around you.

It's very similar
to being drunk.

Light-headedness,
a little dizzy, you're confused.

They say it's the effect
of drinking a couple martinis

on an empty stomach.

It can have a euphoric effect
on the diver.

They can be afraid
all of a sudden.

They can lose their orientation.

This is not something that you
want to happen to you

when you're at depth.

Goodman: It doesn't matter
how experienced you are.

This will impact your judgment.

It will impact
your decision-making,

and it changes
how you respond to things.

This can be totally lethal.

Wade:
And there's another spectacular
feature of the dahab blue hole

that could be involved.

Archaeologist beverly goodman
experienced it firsthand

when she dived
the dahab blue hole in 1997.

You're coming down the side
of the coral wall.

You have this beautiful coral
all around the ring,

and then you're
going down in depth.

And below you, it just goes
into the blue,

and it gets darker and darker.

But then this light starts
coming through this large arch.

Wade:
The arch is a strange feature
unique to the dahab blue hole.

At a depth of approximately
170 feet,

it's a mysterious tunnel

that connects the main shaft
to the open sea.

Elliott: Suddenly, you find
yourself into this cavern

which link the sinkhole
with the red sea.

Wade:
Light reflected through the arch
creates a mesmerizing

but incredibly
disorientating effect.

Goodman:
The arch is this incredible
optical illusion.

Clarke:
It is this beautiful passageway
that can appear both small

and large
depending on your position

thanks to the diffraction
of the light going through it.

And then it opens up
to this clear water

going to 1,000 meters.

Wade: It's a huge temptation
for divers

to follow this passageway
out to the open sea.

The dazzling underwater
illusions can make it look

like an easy 30-foot swim.

In fact, it's over 80.

Judging distance underwater
is quite tricky,

especially when
it's clear water.

You really lose perception.

So what you think is close might
not be as close as you think.

What you think is far might
not be as far as you think.

Wade: Could a deadly cocktail
of narcosis,

confusion and optical illusion
be behind these divers' deaths?

Goodman:
You're feeling really good.

You're feeling this is basically
laughing gas at this point,

so you're feeling
a little bit high.

You're seeing this beautiful
light coming through.

You're not exactly where
you're supposed to be,

but the draw of going towards
that light

and going through it
is really irresistible.

Being a confused diver at depth
could be fatal.

Wade:
Is the bedouins' ghostly girl
in fact the fatal attraction

of this beautiful
but deadly place?

Humans love to push the limits,
and I don't know if it's humans

are attracted
to these dangerous experiences.

But I think we really enjoy the
spectacularness of the unknown.

♪

we still have so much to learn

about the spectacular
underwater realm,

but the deadly dahab blue hole
teaches us a valuable lesson.

The world beneath the waves
is a different dimension

where the normal rules
don't apply,

and we forget that
at our peril.