All language subtitles for Drain the Oceans Series 1 Part 3 Gulf of Mexico 720p

NARRATOR: Deep beneath
the tropical waters of
the Gulf of Mexico lies a

seething history of piracy,
slavery and bitter conflict.

FRITZ: The Gulf of Mexico was
the wild west of the sea and
it's every man for himself.

NARRATOR: Imagine if we
could empty the oceans, letting
the water drain away to reveal

the secrets of the sea floor?

Now we can.

Using the latest underwater
scanning technology, piercing
the deep oceans and turning

accurate data into 3D images.

This time, why did a
deadly German U-Boat end up
at the bottom of the ocean off

the coast of New Orleans?

JAMES: Within very short range,
the hunter becomes the hunted.

NARRATOR: Who was on
board this mysterious wreck,
from a time when pirates and

slave traders ruled the waves?

How did a single asteroid
impact in the Gulf of Mexico

wipe out the
dinosaurs around the globe?

KEN: The base of the food
chain is knocked out and
things begin to starve.

NARRATOR: And how did
drilling for oil result in one
of the biggest environmental

disasters in US history?

DAVE: In theory, that well
should have been easy.

NARRATOR: Draining the
oceans shines new light on the
secrets of the Gulf of Mexico.

66 million years ago,
dinosaurs roam the Earth.

Then, in a geological
instant, they are wiped
out, around the planet.

Can draining the
water from the Gulf
of Mexico explain why?

The story begins not in
the Gulf but over 1,500
miles away in New Jersey.

This former quarry is
one of the most important
fossil sites in the world,

because here,
paleontologists discover a
mass prehistoric graveyard.

-This is the boundary between
the cretaceous period, the
age of the dinosaurs and

the age that comes after
that, the Paleogene.

And what we have here is a
bone bed, where we have about
25 fossils per square meter.

Paleontologists have never
found an in-place dinosaur
bone one centimeter above that

extinction layer
anywhere on the planet.

NARRATOR: The absence
of dinosaur fossils above this
layer can mean only one thing.

They were wiped
out by a sudden,

cataclysmic event,
66 million years ago.

-Whatever took out
the dinosaurs was global,
terrible and instantaneous.

NARRATOR: Experts have
offered many answers.

But only one is
widely accepted.

-By far the leading
explanation is that an
asteroid hit the earth

66 million years ago and
unleashed hell on earth
and took out the dinosaurs

and 75% of life.

NARRATOR: Scientists
scour the planet.

Looking for evidence
of asteroid strikes.

But none of the impact
craters that they find are
big enough and of the right

age to be the culprit.

Then, in Mexico's
Yucatan peninsula, they
find a surprising lead.

Mario Rebolledo, is an
expert in a remarkable
natural phenomenon found all

over this region.

Sinkholes, known
locally as cenotes,

formed by the
erosion of soft limestone,

they can be
hundreds of feet deep.

Exploring them requires
years of experience.

NARRATOR: Mario discovers
that many of the cenotes
are linked through deep,

subterranean channels.

But that's not all.

They also display a
remarkably similar structure.

NARRATOR: When seen from
above, an extraordinary
picture begins to emerge.

The cenotes form an outline.

It looks like the rim
of a gigantic crater.

The most likely explanation is
that a massive asteroid strike
reshaped this region and then

the sinkholes formed in
fault lines around its edge.

Could this be the crater
that's linked to the
death of the dinosaurs?

Today, millions of years after
it was created, the heart of
the impact site lies concealed

not just under the waters of
the Gulf of Mexico, but under
several thousand feet of

sedimentary rock.

The only way to calculate its
age and see if it dates from
the demise of the dinosaurs is

to analyze rocks from
the crater itself.

SEAN: To really
understand impact cratering
we actually need to pull rocks

from ground zero.

We need to find a place where
we know that the damage has
been the greatest in

order to get a sense of
the way impact craters work.

NARRATOR: In 2016,
an international team of
scientists drill down from

this specially
adapted oil platform.

SEAN: And so, we were
pulling up limestone after
limestone after limestone.

We're getting ages from
the fossils within them.

We know we are at 48
or 50 million years but
we're not yet at 66, right.

And then things
suddenly jumped in time.

NARRATOR: The team
hits a layer of melted rock,
indicating an asteroid strike.

And samples confirm
that the rocks are
66 million years old,

the exact moment when
the dinosaurs died.

Next, the team analyze
the rocks to calculate
the asteroid's power

comparing their data
to that generated by
nuclear bomb tests.

-And we can come up with
an estimate of the amount of
energy released and that turns

out to be about ten
billion Hiroshima's.

NARRATOR: Using this
data, it's possible,
for the very first time,

to create a 3D visualization
of the crater, now hidden deep
beneath the Earth and discover

how a single asteroid
impact in the Gulf of
Mexico could wipe out

dinosaurs around the globe.

First, the entire Gulf
must be drained away.

As the water recedes,
it reveals a vast
continental shelf running

around the coastline.

The crumpled plain is
thick with sediment, but the
crater is still hidden under

thousands of feet of rock.

66 million years of geology
must now be rolled back,
draining away layer upon layer

of sedimentary rock, until
the impact site begins to
emerge, a sight that no living

creature has witnessed
for 66 million years.

The crater is immense.

Over half a mile deep
and 120 miles wide.

Around its edge towers
the outer rim, formed by
rock ejected from deep

within the Earth's crust.

Now, by studying the crater's
profile, it's possible to
determine the size and speed

of the asteroid.

It's over 7 miles
wide and it travels at
40,000 miles per hour.

And the crater's dimensions
tell us something else.

30,000 cubic miles of
rock are displaced here.

Vast amounts hurled into the
atmosphere, setting off a
devastating chain of events.

-It blows a hole in the
ground about the size of
the State of Massachusetts.

Now all that rock, it gets
pulverized, thrown up through
the earth's atmosphere.

It starts to orbit the
planet and when that
rock comes back in,

it's got a tremendous
amount potential
gravitational energy.

it heats up the atmosphere
to toaster oven or
pizza oven temperatures,

frying everything that
doesn't have a place to hide.

NARRATOR: Almost every
living creature within
600 miles is killed by

this deadly fireball.

But those further
away do not escape.

-Later that day the tsunami
waves wash up on the shore.

These could have been hundreds
of feet tall, maybe even
half a mile tall when they hit

here, and they would have
run up through the continent.

Animals that are still
alive would have heard
the wave coming for them

but wouldn't have seen
it in the darkness.

NARRATOR: But the
asteroid strike becomes a
truly global disaster for

one specific reason...

where it hits Earth.

This part of the
planet contains rocks
high in Sulphur.

On impact, the Sulphur
is vaporized and blasted
high above the Earth.

-Well that Sulphur combines
with the atmosphere and
becomes sulphate aerosols and

sulphate aerosols
are excellent at
blocking sunlight.

NARRATOR: This deadly cloud
shrouds the planet and
the Earth begins to cool.

By studying the crater in
more detail it's possible to
see new evidence of how the

crater's shape makes
the Sulphur cloud
even more deadly.

The north-east rim is open.

The asteroid hits
deep water here absorbing
some of the impact and

thirty minutes later
the ocean rushes back in.

Water vapor from
this tsunami combines
with the Sulphur to form

sunlight- blocking gases
in even larger quantities.

-The plankton in the ocean
can't do photosynthesis and
pretty soon the base of the

food chain is knocked out
and things begin to starve.

NARRATOR: Lack of sunlight
means the entire planet
experiences an average cooling

of 47 degrees Fahrenheit
for up to 16 years.

Only the toughest plants
and animals survive.

The dinosaurs do not.

One question remains,
was this event unique or
could it happen again,

this time
wiping out human-kind?

-There are other near-Earth
objects out there, asteroids
just like the one that took

out the dinosaurs and we do
not know where they all are.

Every day, scientists
are discovering more and more
asteroids that have the power

to menace our earth.

SEAN: Now, we think we've
tracked all the big ones.

So, we don't think there
is another event that is
just around the corner,

but that doesn't mean we
shouldn't keep making sure,
given the circumstances.

NARRATOR: As we drain
the Gulf of Mexico further,
it's possible to reveal areas

where humans are drilling
thousands of feet below
the sea bed

to exploit a natural
resource formed 100
million years ago...

oil.

But how did a failure while
drilling in the Gulf of Mexico
turn into the biggest oil

spill in US history?

NARRATOR: The economy
of the Gulf of Mexico
is driven by oil.

This vast, oil rich basin
accounts for 17% of
total US crude oil production.

Nearly half of America's
oil refining capacity
sits along the Gulf coast.

But it's offshore that the
scale of the infrastructure
needed to bring oil to the

surface is truly staggering.

Using the latest data and
visualization techniques,
draining away the waters of

the Gulf of Mexico
exposes an extraordinary
underwater world,

normally hidden in the
dark depths of the ocean.

But how did an accident here
cause the worst environmental
disaster in the history of the

Gulf of Mexico?

Pumpjacks like these,
introduced in the 1920s, can
only extract oil in very small

quantities, on land.

DAVE: An old well like this
is perhaps producing only
10 barrels per day of oil.

This is old technology.

This is on the twilight
of an oil field.

You can tell that because
it's nodding up and down.

That means that the
pressure in that reservoir
down there is low.

It's about ready
to be finished.

NARRATOR: In the 1940s,
oil companies discover a
far more productive source,

below the waters of
the Gulf of Mexico.

Here, the oil doesn't
need to be pumped.

It flows.

And the reason lies deeply
embedded in the unique
geology of the Gulf.

JAMES: The Gulf of Mexico is one
of the more oil rich areas on
the planet because out beyond

us was once an ancient
swamp 300 million years ago.

That swamp now is
not only under the water,
it's underneath the earth.

And as a result of
pressure and heat all of
that organic material has been

transformed into oil.

NARRATOR: To produce
an oil field, three
things are essential.

A layer of kerogen,
the organic compound
which creates oil.

A permeable rock such
as sandstone known as
'source rock' for the oil

to accumulate in.

And a trap: a layer of
impermeable rock above, to
prevent the oil dissipating.

By drilling down through this
hard layer, it's possible to
extract the oil and gas from

the reservoir below.

And the Gulf's
continental shelf provides the
perfect base for

offshore drilling platforms.

-When you look out over the
Gulf of Mexico and you see
this flat expanse of water,

most people don't realize
that this is very shallow.

You can go 50 to
100 miles out but
it's only 100 feet deep.

NARRATOR: Since the first
platform was constructed
just a mile offshore,

the network has
expanded greatly.

Around 3,500 platforms
now sit off the coast.

But it's only by draining
the ocean that it's possible
to see the sheer scale of the

infrastructure hidden
beneath the waves.

As the water recedes,
these huge structures
are left high and dry.

There are more oil
platforms here than in the
rest of the world combined.

In the 1970s companies begin
to move off the continental
shelf into ever deeper waters

to tap into even
bigger reserves.

Operating in the Gulf's
very deepest regions, up to
10,000 feet below the waves,

where conditions are
extremely hostile.

DAVE: It is completely black.

Temperature down there
is just above freezing.

You're drilling another
sometimes 20,000 feet below
the seabed and it gets

extremely hot.

So you have this big contrast
between something that's very
hot to something that's very

cold, let alone the extremely
high pressures that we have.

NARRATOR: Today, there
are around 50 deep-water
rigs sited in the Gulf.

Continuing to drain its waters
beyond the continental shelf
reveals the huge scale of

infrastructure needed
to bring oil to the surface
from these super-deep wells.

Clusters of well-heads control
the flow of oil and gas
from deep below the sea bed.

The pressure in the wells
can reach up to 22,000
pounds per square inch.

The well-heads connect
to a central manifold,
up to 100 feet high,

which controls the flow
of oil and gas from
across the oil field up

to the production rig.

The rig separates the oil and
gas before they're transported
to shore by pipeline some

stretching for hundreds of
miles as they wind their
way along the sea bed.

An incredible 43,000 miles
of pipeline snakes across
the floor of the Gulf.

With oil reserves close to
shore now becoming depleted,
companies continue to search

the Gulf of Mexico for new,
more productive oil fields.

Special rigs, costing
nearly half a million
dollars a day to operate,

drill exploration wells
called wildcats, reaching
miles below the sea bed.

One such rig is called
the Deepwater Horizon.

DAVE: The Deepwater Horizon
is an exploration drilling rig.

We use what we call mobile
drilling units to come in
and drill the initial well.

If we find oil we run
casing down there we cement
it off and then we move that

exploration rig off
location and then
come back later to put on

the production equipment.

NARRATOR: In 2010,
the Deepwater Horizon strikes
oil 50 miles off the coast of

Louisiana in an area
codenamed Macondo.

-In theory that well
should have been easy
in that the water depth

about 5000 feet.

We have been drilling in 5000
feet of water since 1979.

The pressure wasn't
too high either.

However, we are in
a very potentially
dangerous industry.

REPORTER (over TV): Now
another major story developing
in the Gulf of Mexico.

Eleven people are missing
after an explosion and fire
on an off-shore oil rig.

REPORTER 2 (over TV):
The explosion happened
aboard a mobile offshore

drilling unit called the
Deepwater Horizon.

It erupted with 126
people on board.

NARRATOR: The cement lining,
designed to seal the well
before the rig moves away,

has a leak in it allowing
oil and gas to force their
way up to the rig and ignite.

After burning for two
days, the rig sinks.

The eleven missing
workers are never found.

In the aftermath, 60,000
barrels of oil per day
escape into the Gulf.

With the well-head a
mile underwater and the
oil pressure so high,

engineers can't stop the flow.

-In the immediate aftermath
of the disaster even while
the well was flowing the

government stopped all
deep-water drilling in the
Gulf of Mexico and rightly so

until we could figure out what
had happened and what you need
to do to be sure not only it

doesn't happen again
but if it does happen
that you have equipment so

that you can stop
it immediately.

NARRATOR: To seal the Macondo
well, engineers design
a solution from scratch...

a capping stack to latch
over the well-head, working
remotely at incredible depths.

By the time the well is sealed
87 days after the blowout,
nearly 5 million barrels of

crude oil have escaped.

The worst environmental
disaster ever to strike
the Gulf of Mexico.

The wreck of the
Deepwater Horizon now
lies on the sea bed.

But it's not alone.

Human commerce began in the
Gulf of Mexico hundreds of
years before the oil and gas

industry took hold.

As the water continues to
drain away, an extraordinary
relic of the region's maritime

history is about to be
revealed from a time when the
Gulf became a superhighway for

pirates and smugglers
trading in the most valuable
'commodity' of the age...

human life.

NARRATOR: Oil and gas
exploration means the seabed
of the Gulf of Mexico is

surveyed in fine detail.

And the search for
oil regularly uncovers
long-lost shipwrecks.

Including a mysterious
ship 150 miles
south of New Orleans.

As the water
of the Gulf of Mexico
continues to drain away,

it will be exposed to
the sky for the first
time in 200 years,

giving an extraordinary
insight into a period
renowned for piracy,

smuggling and slavery.

Who was on this mysterious
ship and what was its cargo?

Sitting at the mouth of the
great Mississippi River,
New Orleans,

in the early 19th century,
expands rapidly.

FREDERICK: New Orleans
was basically a bustling
maritime entrepôt.

I mean, this was one
of the largest ports in
the western hemisphere and

it was situated centrally
in the Gulf of Mexico.

And so, you have
hundreds of ships coming
and going, importing,

exporting all sorts
of different kinds
of trade goods,

but you're also seeing an
increase in illicit activity
from slave trade to smuggling,

and, and this
place is just booming.

NARRATOR: Hard evidence
of this extraordinary
period of maritime history

is extremely rare.

Then, in 2011, an oil company
identifies a wreck, giving
it the name 'The Monterrey'.

FREDRICK: This particular
shipwreck lies on the sea
floor at an approximate

depth of 4500
feet or almost a mile,

which makes
it really difficult to get to,
but it also means it's going

to be that much
better preserved because the
temperature at that depth is

four degrees Celsius and
that really slows the
rate of decomposition.

NARRATOR: The team
launch a state of the art
remotely operated vehicle,

or ROV, to investigate.

FREDRICK: The ROV
takes four hours to get
down to the sea floor

and so, you know,
there's this anticipation.

When the ROV hits the
floor and cruises up to this
particular site and we lay our

eyes on the shipwreck
for the first time, we're
astounded, we're excited.

Because what we're
looking at is a largely intact
ship almost a mile deep in the

Gulf of Mexico and it was
just mind-blowing.

NARRATOR: As the ROV
travels over the wreck it
sends back tantalizing glimpses

of the ship and its contents.

-At this depth in the
ocean it's pitch black,
there's no light,

you can't see anything
unless you light it up.

So, when we're working on
sites like this in particular,
we're only getting snapshots

or small glimpses
of the site itself.

We don't have the entire
picture while we're
viewing the ROV footage.

NARRATOR: The ROV also
captures precise data from
on-board sonar equipment.

Combining this with the latest
visualization techniques,
it's now possible to drain

the ocean and pull the plug
on more of the Gulf of Mexico,
letting archaeologists view

the wreck from any
angle and examine it
in unexpected detail.

Will seeing it for the first
time in 200 years help them
discover what it was doing,

how it came to lie on the sea
bed and the biggest mystery
of all: who was on board.

As the water recedes,
the ship is revealed.

The bow, sheathed
in copper to protect against

marine organisms, still intact
and the anchor still stowed.

Chain plates, once used to
secure the rigging, indicate
it had two wooden masts,

long lost to the ocean.

With the water gone, six
cannon lay exposed to the sky.

And around the stern,
lying on the sea floor,
a cache of muskets.

JAMES: What struck me was
this was a ship that
was very long and narrow

particularly at the bow.

It struck me as almost
being like a clipper ship, a
specific type of vessel that

came into the fore really
in the early 1800s.

NARRATOR: Clippers
were perfectly suited to
the Gulf of Mexico due to

their shallow draft,

ideal for navigating
the Gulf's coastal
waters and marshy bayou.

-What also struck us
was that it was armed.

It had cannon, and there were
muskets, was it a warship,
was it something else?

NARRATOR: Is it a privateer?

-A privateer is basically
an individual that has written
permission or letter of marque

or letter of commission from
a respective government giving
them permissions to capture

ships, to make incursions
on enemy soil in the name
of that particular country.

-Privateering is basically
state sponsored piracy, in
which the privateer gets a cut

of the action and the
rest goes to the state
that's licensed them.

NARRATOR: In the first
two decades of the 19th
century there are hundreds

of privateers in
the Gulf of Mexico.

But as the ocean drains
even further away from
around the Monterrey,

there's a twist to this story.

The wreck is not alone.

As the water disappears, a
complete picture of the entire
sea floor begins to emerge for

the very first time,
revealing the remains
of two other ships,

each containing further clues.

-It's really exciting to have
one shipwreck but when all of
a sudden you go from one to

three it gets incrementally
more exciting because now
we're not talking about just

one wreck we're talking
about a potential convoy.

NARRATOR: Wreck A, the first
ship discovered, is heavily
armed with cannon and muskets

for close quarter combat,
leaving researchers to think
it could be a privateer.

With wreck B, it's clear
that the wooden hull has
been consumed by the ocean.

But its cargo is still intact.

It's carrying animal hides,
a valuable commodity at the
time and frequently traded.

Treated and rolled
for shipment, they are well
preserved by the cold waters.

Wreck C, exposed to the
sky for the first time in
200 years, is a larger,

three-masted vessel.

But amongst this wreck,
there's no cargo to be found.

-What does that mean?

Well it means the ship
was either sailing in
ballast, that is empty,

or it had a cargo that
was perishable, and that
perishable cargo could have

been everything from rice
or grain, to one possibility
being a very sobering thought

and that is it could have
been carrying people.

It may have been a
vessel engaged in the
illegal slave trade.

NARRATOR: The trans-Atlantic
slave trade sees slaves
violently captured and

shipped from West Africa,
and then forced to work on
US plantations.

Although owning slaves
remains lawful, the import
of new ones is outlawed by

Congress in 1807.

Great Britain also
bans the trade and uses
its navy to hunt down and

capture slave ships.

With much money
still to be made,

smugglers continue to
bring captured African men,

women and children through
the Gulf of Mexico and into
its maze of channels and

waterways, aiming for New
Orleans and its slave markets.

Is wreck C involved in this
brutal, callous business?

-Now we didn't see manacles or
anything of that sort but in
this period, when it's lost,

it's entirely possible, as we
know from other cases, that
people were simply locked

below in the hold, and
with those that were most
capable of trying to escape

being tied up.

NARRATOR: The team begin to
piece together the evidence.

-In thinking about
these ships as a convoy,
we can hypothesize a

variety of scenarios.

The first would be it's an
armed escort with two merchant
ships that need protection to

get from one port to another.

It could be a privateer with
two prizes that it captured.

In looking at the cargo on
the second ship we have stacks
and stacks of cow hides.

Those would have brought a
great price at the market,
even if you were smuggling.

NARRATOR: To unravel the
mystery further, they select
a range of artifacts and bring

them to the surface.

They could reveal once and
for all who was on board.

AMY: One of the unique
things about this particular
shipwreck Monterrey shipwreck-A

was the cannons and
the presence of muskets.

Those were all British types,
British military musket types.

They were absolutely
ubiquitous in this region
during the first half of the

19th century, so
having British muskets on a
ship does not mean that it's

a British vessel.

NARRATOR: The crews'
nationality remains a mystery.

But there are other clues
that may tell us what
caused the ships to sink.

AMY: A portion of the
collection that was recovered
were navigational tools.

The importance of these tools
was so great that you would
have wanted to have taken

those with you so leaving
them on the ship is
foreboding and you know,

it suggests that maybe
everyone perished.

NARRATOR: The Gulf
of Mexico is notorious for a
particularly violent force of

nature: hurricanes, giving
rise to one likely scenario.

JAMES: All three of them
were running together
in what clearly was a

very violent storm.

You had a quick moment
to look on the horizon,
see the other guys there and

then their lights disappear
if it's at night or they
disappear in a squall.

And the next thing you know
the Gulf is coming over your
own decks and you're being

dragged down into the depths,
and into the darkness.

NARRATOR: The Monterrey
group of wrecks provides a
new insight into the maritime

history of the Gulf of Mexico,

at a turning
point in US history.

FREDRICK: The Monterey
shipwrecks are important because
they're evidence of that

transition to the
birth of a new nation.

How trade continued while
the Spanish empire crumbled.

Why New Orleans was
such an important part
of this interregional,

burgeoning global trade.

And that's what those
shipwrecks speak to and that's
what they're symbolic of.

NARRATOR: The Monterrey
wrecks are not alone.

As the water drains
away further, leaving
the darkest depths of the

Gulf of Mexico exposed,

one of the most
extraordinary stories of
all is about to be revealed:

a state-of-the-art
WW2 submarine, not
American but German.

What was Nazi
submarine U-166 doing
in the Gulf of Mexico?

And how did it meet its end?

♪ ♪

NARRATOR: December 11, 1941.

Hitler declares war
on the United States.

NARRATOR: When the
US enters the war, a new
battleground opens up...

The Gulf of Mexico.

Today, by draining away its
dark waters, it's possible
to reveal secrets from this

desperate period of conflict,
when a ruthless battle to rule
the waves comes to America's

own shores and solve
a mystery which has baffled
historians for over 70 years.

Immediately after
entering World War II,
the US faces a deadly peril,

off its eastern seaboard.

Nazi U-boats.

Their objective is to
disrupt Allied shipping bound
for Europe, at the source.

The U-boat commanders
are highly experienced,
having honed their skills

in battle since 1939.

The United States
is completely
unprepared for them.

ERIC: Ships were escorted
across the North Atlantic
in convoys both ways.

But once they got into
American coastal waters
they were unescorted,

and they were therefore easy
targets for the U-boats.

NARRATOR: To make matters
worse, the US government
fails to impose a blackout.

Ships sailing along
the coast at night are
perfectly silhouetted.

Sitting ducks.

-And this was a key
vulnerability the
Germans noticed,

and they sent their
submarines in to exploit it.

NARRATOR: German submarine
commanders call it
'American shooting season'.

Between January and
June 1942, more tonnage
is sunk off the U.S.

coast than the Allies
have lost during the
previous two and a half years,

as the Nazis try to starve
Britain of vital supplies.

The U Boats then take the
war into the Gulf of Mexico.

And the reason is oil.

-Most of the world's oil
at this time came through
the Gulf of Mexico,

hence it was the equivalent
to the Arabian Gulf today.

NARRATOR: It's
not just oil tankers.

Any Allied ship is
seen as fair game.

JAMES: A U-boat skipper
did not want to pass up on the
opportunity to sink what might

be a valuable cargo of
a specific commodity,
be it foodstuffs,

be it machinery or parts.

He couldn't know for certain,
but he did know that if he
sent a ship to the bottom he

was aiding the
German war effort.

NARRATOR: One such
ship is the Robert E Lee.

ROB: The Robert E. Lee
was a passenger freighter.

It was coming from Trinidad
up to New Orleans and it
actually was carrying American

construction workers and
also a lot of other
passengers that were victims

on previous U-Boat sinking's.

NARRATOR: As the Robert E Lee
approaches New Orleans,

U-166 is on patrol.

One of the latest German
long-range submarines, U-166
is capable of traveling across

the Atlantic without
the need to refuel.

A thoroughbred ocean predator,
commanded by battle-hardened
Captain Hans Gunther Kuhlmann.

ROB: Hans Gunther Kuhlmann
had not had a lot of success
during this mission.

He had sank a couple of
small boat, including one
that was just a few tons.

It actually bore the same
name of his wife, Gertrude.

And so as soon as he saw a
large vessel over 5,000 tons,
it was a big target and it was

an opportunity for him to get
some tonnage under his belt.

NARRATOR: The
details of the battle,
including the fate of U-166,

for years remain one
of the Gulf of Mexico's
greatest mysteries.

Rob Church is a marine
archaeologist for a company
performing surveys of the

sea floor for the oil
and gas industry.

When a wreck is discovered,
his job is to assess
its historical importance.

-So, this is a typical
inspection class ROV.

It is a 3,000-meter
rated system.

On this particular one
right now we have three
camera arrays here.

We have the two stereo cameras
for collecting 3D video.

We have the HD camera
above them for collecting
high resolution video.

We also have a seven-function
manipulator arm which allows
us to be able to pick up

things on the sea floor;
collect samples, also ah set
out experiments, etcetera.

And then we have
a scanning sonar.

This allows us to detect
targets on the sea floor to
inspect or we can also use it

navigate around shipwrecks.

NARRATOR: While conducting
an oil pipeline survey using
an ROV similar to this,

Rob Church comes
across a wreck.

ROB: We approached
from the stern and you
could see the railing,

you could see the
decks of that
passenger freighter

and there was no doubt at
that point that we were
looking at the Robert E. Lee.

This was a thrilling moment.

And to see a boat
like the Robert E. Lee,

which is really a
beautiful wreck site,
it was incredible.

NARRATOR: Over 5,000 feet
down, the ROV scans the site
collecting valuable data.

From this, it's possible to
drain away the ocean and see
the drowned vessel as she is

today but this time,
exposed to the sunlight.

As the water pours away,
the wreck of the Robert E Lee
is revealed in extraordinary

detail, providing new
evidence on her final moments.

The bridge is gone, unable
to withstand the forces of
drag as the ship plummeted

through the water.

The deck gun on the stern
is in the stored
position showing the attack

is sudden and unexpected.

And lying next to the
wreck are two lifeboats.

The speed with which the
ship goes down does not give
the crew time to deploy them.

Experts calculate that it
takes just three minutes for
the Robert E Lee to sink.

But one important part of the
puzzle remains unanswered.

What happened to the U-boat
that fired the deadly torpedo?

As the water continues to
drain away from the wreck
of the Robert E Lee,

one of the Gulf of Mexico's
biggest maritime mysteries
is about to be solved.

NARRATOR: July 30, 1942.

The German submarine
U-166 fires a fatal shot
at the merchant vessel,

Robert E. Lee off the
coast of New Orleans.

It sinks in three minutes.

But the Robert E Lee
is not alone.

It's escorted by a submarine
chaser Patrol Craft 566,
captained by Herbert Claudius.

ROB: The indications are
that the U-Boat had no
idea that the patrol craft was

bearing down on them.

They were proceeding at
periscope depth watching the

Robert E. Lee sink.

It wasn't until the patrol
craft got within range and
began actively pinging sonar

against the hull that
they first apparently realized
they were under attack at that

moment and began to dive.

JAMES: Within very short range,
the hunter becomes the hunted.

NARRATOR: As Patrol Craft
566 passes over the U-boat,

Captain Claudius fires
two rounds of depth charges.

Unable to confirm a kill,
he turns his attention to
rescuing survivors

of the Robert E Lee.

The fate of U-166
remains unknown.

Two days later a US Coast
Guard plane spots a U-boat
surfacing 140 miles away.

It drops a single depth charge
and the U-boat disappears.

The plane crew is credited
with sinking U-166.

But despite extensive
scanning of the sea floor,

no trace of a
wreck is ever found.

-Finding something that so
many people had looked for so
long it's kind of you know,

it takes an element of luck.

NARRATOR: Studying a
sonar scan of the sea bed
around the Robert E Lee,

Church spots a mysterious
object, less than two
miles away from the wreck.

ROB: So, as I first saw
the image I realized it
had potential.

But it was about 50,
60 feet short of the dimensions
of a Type 9C German U Boat.

NARRATOR: What was this
mysterious wreck, 140 miles
away from where U-166 was

believed to have sunk?

Could it be the missing sub?

Further draining of the
ocean uncovers the truth.

As the water recedes,
light begins to pour
onto this mystery vessel.

The conning tower of a German
U-boat gradually appears,
its antenna unretracted

indicating it dived suddenly
and under duress.

Next, its hull is exposed
to the sky for the first
time in over 70 years.

The configuration of
the conning tower and
deck guns exactly matches

the missing U-166.

And from another angle,
the reason the sonar image is
short suddenly becomes clear.

The U-boat's bow is
missing, blown off by
a massive explosion.

As the water continues to
drain away, the missing
section is revealed,

lying 500 feet away.

A depth charge alone
could not have caused
such catastrophic damage.

So, what happened?

-It appears that after one of
the depth charges breached the
pressure hull that it probably

set off an internal
explosion which then
ripped the bow section off.

ERIC: When the submarine
dived, perhaps torpedoes
became loose and it was more

likely that an
explosion would occur.

This was a successful
depth charge attack and it was
clear that this was actually

sunk as claimed by the
submarine chaser.

NARRATOR: 22 people lost their
lives on the Robert E Lee and
all 52 perished on the U-166.

The two wrecks are now
considered a war grave
and cannot be salvaged.

Draining the ocean is
the only way to bring the
wrecks to the surface and

in the process set
the record straight.

With the U-boat
discovered lying less than two
miles from the Robert E Lee,

there can be no
doubt who sank it.

The kill is now credited to
Herbert Claudius, captain
of Patrol Craft 566.

Soon after the sinking of
U-166, the tide begins to turn
in the Battle of the Atlantic.

-Inevitably, the Allies
were able to push back against
the U-boat assault thanks

to a variety of factors.

Increased surveillance,
more convoys, as well as the
ability to strike from the air,

the U-boats were
steadily defeated.

NARRATOR: Nevertheless,
during the Second World War,
while operating in US waters,

the German navy sends 609
Allied ships to the bottom
of the ocean with the loss of

only 12 U-boats.

Of those, only one
submarine is sunk in
the Gulf of Mexico...

U-166.

Looking below the waters
of the Gulf of Mexico has
solved long lost mysteries and

brought deadly secrets back
to the surface showing that
the story of North America:

through trade, war
and even the death of the
dinosaurs can only be fully

seen and understood
by draining the oceans.

Captioned by Cotter
Captioning Services.