All language subtitles for Drain the Oceans Series 2 03of12 Killer U Boats 1080p

Narrator: World war I.

A new stealth
weapon brings terror
to the oceans.

Delgado: This is a dirty war.

Narrator: Evidence
of a naval revolution.

Lost for a century
beneath the storm ravaged
seas of the british isles.

Imagine if we could
empty the oceans.

Letting the water
drain away to reveal the
secrets of the sea floor.

Now we can.

Using accurate data and
astonishing technology...

To bring light once
again to a lost world.

Why do three royal navy
warships simply disappear?

Grove: The british
are shocked.

Narrator: How does a
single torpedo change
the course of history?

Eoin: For a shop of
that size to disappear in

Less than 20 minutes
was just incredible.

Narrator: And how
do the allies strike back
in a battle that changes

Naval warfare forever?

(theme music plays).

Today's superpowers prize
one weapon above all others.

The submarine.

The ultimate stealth weapon.

Striking at will.

Delivering its deadly
payload from out of nowhere.

But the rise of the submarine
started a century ago.

It's a story that begins
with a mystery off
the coast of holland.

The corpse of an
enormous ship emerges.

And not just one.

Three broken giants
lie side by side.

How did they get here?

1914.

Britain and germany go to war.

Britannia has ruled the
waves for centuries.

Her fleet so massive, how
can germany ever hope to win?

Just seven weeks into the war.

Hms aboukir, cressy and
hogue scan the horizon
near the dutch coast.

Their mission seek and
destroy any enemy that dares
to threaten british vessels

Supplying the battle
fields of France.

Grove: It was there
as a screen against serious
german surface attack on

These vital cross
channel supplies.

Narrator: The three
ships are packed with
cutting edge technology.

Among the first ever
protected by super
hardened steel plate.

A whole new
class of warship...

Armored cruisers.

Grove: These are
powerful ships.

They'll blow you out
the water if they see
you on the surface.

They're armed
with twelve 6 inch guns,
two 9.2 inch guns, each.

Narrator: The morning
of September 22nd
is clear and calm.

There's no enemy in sight.

Yet the three cruisers vanish.

Their last communication,
a distress signal.

In the weeks that follow,

Hundreds of bodies wash
up along the dutch coast.

Britain's belief that
her navy is invincible
is rocked to the core.

For a decade,
klaudie bartelink has
been investigating the fate

Of the lost patrol.

Now she's onto something.

Bartelink: So we're 20
miles off the dutch coast,
over there is England,

And over there
is the netherlands.

I try to find the three
cruisers and figure out
what has happened to them.

Narrator: She's on the
last known coordinates
of the three ships.

115 feet down klaudie
and her dive buddy find
themselves among piles

Of twisted wreckage.

The wreck site is massive,

Stretching for hundreds
of feet into the darkness.

Klaudie's exploration
reveals that there's more
than one vessel here.

And her lights pick
out something else.

Strewn all around shells
still in their casings.

Never fired.

Bartelink: I saw a
lot of ammunition.

I saw here the boxes
with small shells.

It's has to be
a military ship.

And on these coordinates
they're definitely
cressy, hogue or aboukir.

Narrator: A positive id,
but in the gloom it's
difficult to see how

The ships met their end.

Bartelink: It's very
hard to understand the
shape of the ship below

Because you only
see part of the ships.

And you can't recognize
like the bow or something.

It's, it's impossible.

Narrator: High tech sonar
scans provide a solution.

Mapping the wrecks
in perfect detail.

Allowing us to do something
never possible before.

Drain away the
english channel to see
the lost patrol clearly

For the first time
in over 100 years.

The warships
bristle with guns.

Including these, innovative
side mounted weapons
called casement guns.

On the smooth hull
of aboukir there's no
sign of battle damage.

But near the stern
a gaping wound.

On the other two
wrecks fatal blows
also clearly visible.

Hogue's hull is broken open.

Cressy's interior
completely exposed.

Damage like this,
far beneath the waterline,

Is hard evidence that
a terrible new weapon

Is in play.

Bartelink: So what
you see where torpedoes
went into the ships.

And I think this is the
moment that the naval
warfare changed forever.

Narrator: Torpedoes are
self-propelled and deadly.

Flying under the waves they
strike below the waterline.

Delgado: The torpedo, as
initially developed and tested
through the 1860s and 1870s,

Is truly refined,
in world war I.

Narrator: They are
originally fired from ships.

But on the day of the lost
patrol the horizon is empty.

The source of the
torpedoes must lurk unseen.

Unable to defeat the
royal navy's massive battle
fleets on the surface.

The germans are
deploying new technology
under the waves.

They call them,
'unterseeboote'.

U-boats.

The british cruisers
are completely unprepared.

Grove: What they weren't
expecting was this covert,
underwater attack,

Which is carried
out with great skill.

Narrator: Unfired
ammunition on the sea-bed
shows that the cruisers

Don't put up much of a fight.

By the time they spot
torpedoes running the
battle is already over.

Delgado: U-boats
are a game changer.

Narrator: The way
the drained ships lie
close together reveals

That they were sitting ducks.

As the first goes
down the other two race
in to rescue survivors,

Giving u-boat number nine

The perfect opportunity
to pick them off with ease.

They still lie
where they fell.

Side by side.

Grove: The sinking othe
three cruisers, aboukir,

Hogue and cressy,
demonstrated the power

Of the submarine perhaps
more than anything else.

Narrator: The dutch
authorities bury the british
dead with military honors.

Bartelink: In the
netherlands it was big news.

It was in all newspapers
because in one and

A half hour almost
1500 men died and 13
of them were teenage boys,

So it was
a very big story.

And they were buried
here, honorably.

There were soldiers
along the road,

They paid a lot
of attention to it.

Narrator: U-boats
are so effective because
german engineers have

Overcome some massive
technical challenges.

And how they manage
this can still be seen
because, remarkably,

The very first
u-boat survived.

Koerver: This is u-1,
germany's first submarine,
over 100 years old and

You could make some
5 or 6 hours submerged
with electric engine

At slow speed 5-6 knots.

Narrator: Electric engines
power the 139 foot long
vessel when under water.

Its batteries
are recharged
by 2 gasoline engines,

Which run the
u-boat on the surface.

Koerver: We have two
different pairs of engine.

Two gasoline and
two electric motors,

So it's like a modern
car, a hybrid system.

Narrator: U-1 can dive
to 100 feet and travel
submerged for 50 miles.

But for their crew,

U ats are
unforgiving places.

There's deafening
engine noise, exposed
electrical circuits.

And if sea water gets into
the batteries deadly chlorine
gas will quickly spread.

Mccartney: If you're
serving in submarines,

You've got a higher
change of dying than

You have if you're
on the western front.

Narrator: U-boats maybe
dangerous for their crews,

But they're lethal
to their enemies.

And the germans
have boats almost
three times bigger

Than u-1 on the drawing board.

During 1915 germany
expands its fleet to over 50.

And that's just the start.

Koerver: The climax
was reached with the number
of 125 available submarines,

Means around 30, 40
submarines were at sea daily.

Narrator: And this
expanding u-boat force
doesn't just have military

Targets in its sights.

Grove: There were
elements in the german navy
who quite deliberately wanted

To achieve what
you might call a form
of maritime terrorism.

Narrator: The
killer u-boats target
a world-famous ship in

An attack that
shocks the world.

By 1915, no
allied ship is safe.

Off ireland's southern coast,

Eoin mcgarry
investigates what happens
when the german navy

Dramatically
escalates its campaign.

Eoin: It's under the water,
you can look around, you don't
know where it is,

You don't know where
it's going to attack from.

How do you attack back?

Narrator: U-boats entering
service in the second year
of the war could dive almost

Twice as deep as u-1 and
run submerged for 80 miles.

Increased range means
they can now strike
deep into the atlantic.

And soon the german navy
is making the most of
its killer technology.

Beneath this buoy lies
the wreck of one the most
iconic ships in history and

Its shocking secret.

Eoin is one of a select
few experienced enough
to make the dive.

It's so deep he must
breathe a special mix
of gases to stay alive.

Eoin: It's like the
everest of diving, it's
just within the realms of

Safety and the limitations
of your qualifications.

Narrator: He heads down over
300 feet into the darkness.

This twisted wreckage is
all that remains of one of
the most luxurious passenger

Liners ever built.

But for over a century
the power of the sea
has taken its toll.

Eoin: On a huge wreck
like 798 foot long it
still lies as a huge hulk

On the sea floor.

It's festooned
with fishing nets,

Discarded fishing nets,
tangled fishing nets.

It's a dangerous dive.

Narrator: It also
hides clues to an
atrocity so shocking,

It changes the
course of the war.

This is the wreck
of rms lusitania.

On may 1st 1915...

Lusitania leaves
new york for britain.

Like her ill-fated
rival titanic,

This massive liner
has been engineered
to be unsinkable.

On board nearly 2000 souls.

Eoin: It was like a
floating 5-star hotel.

In one end of it and
then for the third-class
passengers it was still

A luxurious way and fast
way of crossing the atlantic.

Narrator: Six days later,

Lusitania is just 12 miles
from the irish coast.

Her captain has been
warned that u-boats
are in the area,

But lusitania can
surely outrun any threat.

Eoin: The lusitania
was doing 24 knots
when she was cruising and

If you look off the stern
in the lusitania you could

Put 60 water skiers
across the water and she
could pull water skiers,

She went that fast.

Narrator: So why
does this super liner,

Built to be invincible,
never arrive?

300 feet down...

Clues are hard to spot.

But feeding precise 3-d
scanning data into powerful
animation software

Means we can now
reveal the wreck of

One of the most famous
ships that ever sailed.

Lusitania slowly emerges
back into the light.

32,000 tons of scarred
and twisted metal.

She lies tilted on
her starboard side part
sunken into the sea bed.

Can this be linked
to how she sank?

Now seeing under
the sea floor, itself
it's possible to reveal

Something never seen before.

Evidence of a fatal blow.

Here under the water line
the unmistakable hallmark
of a torpedo strike.

U-20 has been ordered
to stalk these waters.

Not only hunting warships...

Liners too.

The u-boat unleashes
a single torpedo, like
an assassin's bullet.

Eoin: If you could
imagine being on the deck
of the lusitania being six,

Seven story's up
and looking over and you
see this thing coming at

You and you know
it's gonna hit you and you
know exactly what it is...

That must be daunting.

Narrator: Lusitania
is built to take
on huge amounts

Of water yet
still stay afloat.

How could a single shot,

Send a ship this
big to the bottom?

The drained wreck
reveals the hull is
snapped clean in half.

And the tip of the
bow severely damaged.

Evidence the liner
hits the sea floor
with tremendous force.

Now at last we can
reconstruct lusitania's
final moments.

The torpedo blows open a hole.

Lusitania is travelling
so fast that her momentum
forces tons of water in.

She plunges into the
atlantic taking nearly

1,200 men, women
and children with her.

Eoin: She's almost driving
herself underneath the water.

And even if the
props were stopped she
still was 32,000 tons

Still being driven forward.

Narrator: There's
hardly any time
to launch life boats.

Eoin: She was gone
in 20 minutes which must
have been just terrifying

For the people on board.

Narrator: Lusitania's
speed hasn't saved her.

It's killed her.

She hits the sea
bed so fast that her
huge hull snaps in two.

Many hundreds of
bodies wash ashore nearby.

Buried in mass
graves in ireland.

As the whole world
reels in shock.

Delgado: The germans
were seen as murderers,

They were seen
as villains.

Narrator: U-boats are
now a terror weapon.

But it's a risky strategy.

The loss of american
civilians on lusitania and

Further u-boat attacks
on american shipping,

Pushes the us towards
joining the war.

The german navy knows
that the clock is ticking.

Delgado: The germans know
that they have a short
window in which they can

Try to win the war.

If they can get
enough subs out there,

If they can have advances
on the battlefield,

Then they have a chance.

Narrator:
The killer u-boats
launch a new campaign

To crush their
enemy outright.

Waged here just off
the coast of britain.

But the battle
is about to get a lot
tougher for everyone.

Narrator: Lurking
beneath the surface.

Unseen, unchallenged,

The u-boat seems invincible.

Delgado: To counter the
threat of the german u-boats,

The royal navy in particular

Didn't have much that
they could throw at it.

Narrator: U-boats
can hide themselves within
sight of any british port.

The enemy is at the gates.

After sinking lusitania
the u-boat fleet doubles
to over 100 vessels.

They're planning to
land a decisive blow.

Grove: We will sink
enough ships to stop
britain importing and

This will defeat the british,

Who are the
lynch pin of the allies
before the americans,

Who might well
declare war, can bring
their power to bear.

Narrator: Britain's
ports are the final
destination for a vast

Maritime supply chain.

Thousands of merchant
ships bring vital food,

Munitions and supplies
from the british
empire and the usa.

Delgado: The need to
support the war in europe
sees a massive shipment of

Men and material
across the atlantic,

As well as the
movement of ships in and
around the british isles.

The germans know this
and the submarines are sent
out to take those ships out,

With deadly effect.

Narrator: If the
german u-boats can cut
the flow of supply ships,

They can starve britain
into submission and they'll
stop at nothing to do it.

Mccartney: It's a total war.
Civilians are targets.

Merchant seamen are targets.
This is what total war is.

It's not a war between
sailors and soldiers.

It's a war in which
everybody is involved and
everybody will be sacrificed.

Narrator: This war
rages most fiercely
here in the irish sea,

Just outside the important
port of liverpool.

In these seas bangor
university's survey vessel,

Prince madog
is on a mission.

Mccartney: There she is.

Narrator:
Marine archaeologist
innes mccartney has

Joined forces with
oceanographer mike roberts.

Using the latest scanners,

Their ambitious plan
is to locate every
victim of this battle.

And discover what happens
when the u-boats try to starve
britain into submission.

Roberts: In world war I this
stretch of water was a very,
very dangerous place to be.

Narrator: Every
merchant ship runs the
gauntlet to make it through

This corridor of death.

Roberts: It must have been
terrifying knowing what
could happen at any moment.

Narrator: And prince madog's
survey is uncovering the
massive scale of the killing.

Roberts: Immediately
beneath us are the remnants
of a protracted battle, a

Battlefield effectively
which contains
the remains of many,

Many hundreds of shipwrecks.

Narrator: The sonar scans
reveal the scattered bodies
of the u-boats victims.

They prey on any type of
vessel, thousands perish.

Innes and mike study
one wreck closely.

A ship heavily laden with
cargo for the war effort.

Mccartney: We know from
the position of where it is,
combined with the length and

Other details, that we
can see that this is
the wreck of ss apapa.

Narrator: 4:00am.

Nov 28th 1917.

Ss apapa is almost at
the end of her journey
from west africa.

As well as cargo, she's
carrying 119 passengers.

Including many
women and children.

Soon they'll be docking
safely at liverpool.

They hope.

Mccartney: It's coming
into the danger zone where
the u-boats are waiting.

Narrator: Us-96 is in
the perfect position.

Mccartney: The u-boat
had maneuvered round and was
between the land and the ship.

Undetectable against
the background.

Fires a torpedo which
struck apapa in the stern.

And it immediately
began to sink.

The captain on the apapa
ordered the women and children
to be put into the lifeboats,

So the lifeboats are
swung out and they're
put down on the rail.

Narrator: Though apapa
is already sinking, u-96's
commander heinrich jess,

Isn't finished with her yet.

Mccartney:
At this point u-96 has
fired its second torpedo,

What the commander referred
to as the killing shot.

And it was being
hit the second time while
everybody was evacuating and

It caused 77 people to die.

Narrator: The dead
civilians onboard apapa
make this one of the most

Infamous u-boat attacks ever.

But it's just one of many.

Under orders to
sink a monthly quota of
600,000 tons of shipping,

U boat attacks are relentless.

Grove: In fact,
at one month, April 1917,
they get to 800,000 tons,

It's quite massive.

They're doing better
than they expected.

Narrator: National
survival is on the line,

How can the
british fight back?

Delgado: Not only do
german submarines improve
and change during the

First world war,

But also the means by
which to find them and sink
them, also begin to change.

Narrator: Prince madog
has found dozens of wrecks.

Now she picks up a new
signal from the sea floor.

Unlike any seen so far.

Is this evidence of an
under-water counter offensive?

Mccartney: Skinny
and tube-like with a
central high point.

This is a classic
submarine wreck.

Narrator: Among
the wrecks surveyed
in the killing zone,

This is the only u-boat.

So, if u-boats are
so dominant here in 1917,

What is it doing
on the sea bed?

Prince madog's detailed
scan makes it possible
to drain back the

Waters and investigate.

It's an amazingly
well-preserved u-boat.

Frozen in time.

And this fearsome killer's
200 foot long body looks
completely undamaged.

Accurate measurements
from the high res scan
means innes can identify

Exactly which u-boat this is.

Mccartney: The distance
from the bow to the conning
tower, to the stern,

And all of that matches up

Exactly correctly for u-87.

Narrator: It's an
incredible discovery.

U-87 is one of a whole
new class of long-range
ocean-going hunter killers.

It's faster than previous
u-boats and carries
twice as many torpedoes.

A deadly threat.

Mccartney: U-87 was
the best type of submarine
the germans were capable of

Making in 1916 to 1917.

Narrator: What could
its mysterious fate tell
us of the desperate struggle

To stop the killer u-boats?

Narrator: The wreck of
u-87 sits on the sea bed.

Apparently intact.

But over 500 feet across
the drained ocean floor,

Another much smaller piece
of wreckage comes to light.

It appears to be the
very tip of u-87's stern.

What's it doing here?

Aboard survey vessel
prince madog,

Innes mccartney reviews
records of u-87,

Detailing her mission,
and learns more about
the day she is destroyed.

Mccartney: Christmas day
1917, u-87 encounters
a small convoy.

And torpedoes a steamship.

The u-boat's periscope
is subsequently spotted.

Narrator: Royal navy
patrol boat p 56 has
u-87 in its sights.

Mccartney: The
chances of any of these
patrol boats ever seeing

A submarine was remote and
when they did everything
gets used to take them out.

Narrator: And she's
carrying a new kind of
anti-submarine weapon.

An underwater bomb,
called a depth charge.

Delgado: A depth charge is
an explosive that is set,

Once launched or
rolled off the side or

The back of a ship,
to detonate at a set depth.

Narrator: The british
captain gets as close
to the last sighting of u-87

As he can and fires a
volley of depth charges.

But is this what
sinks the u-boat?

Can this small fragment
give us an answer?

Some force has left
it 500 feet away
from the u-boat.

But the edges of the
wound look clean not jagged.

Could a depth
charge do this?

Engineer: Can you
confirm the range is
clear for firing, over.

Man (over radio):
Confirmed, the range is clear.

Narrator: At a
remote defense testing
facility in scotland

Demolition experts
are trying to understand

What effect an underwater
blast can have on a u-boat.

Sensitive equipment
measures the forces a depth
charge unleashes outside

And inside the hull.

Engineer: 60 seconds.

Misselbrook: I wouldn't
want to be in a submarine
when that happens to it,

Cos it's a very violent event.

(air horn)

Engineer (over radio):
5-4-3-2-1.

(explosion)

Narrator: The blast
creates a pulsing shock wave.

But is does not
crack open the hull.

However, the test reveals
that depth charges can
damage subs in other ways.

Misselbrook:
The direct shockwave excites
the submarine, shakes it,

Vibrates it
until equipment fails.

Narrator: If this array
of fragile pipes, valves

And hatches breaks,
that threatens
the u-boats survival and

Exposes its biggest weakness.

Delgado: By setting a
depth charge off underwater
the blast is intended

To rupture the seams,
to break systems,

To rattle the crew,
to concuss them.

Mccartney:
Depth charges had the
immediate effect of driving

The u-boat to the surface.

Narrator: On the surface
there's nowhere to hide.

P 56 seizes the moment.

Grove: A good way of
sinking submarines,
was just to ram them.

They were vulnerable to this.

They could be cut
in half or have bits,

Chunks taken out of them,
by a ship ramming them.

This would sometimes
perhaps damage the ship,

But on the other hand,
on balance it was better

To sink the submarine and
ramming is very important.

Narrator: Risking
sinking itself,

The patrol boat heads on a
collision course with u-87.

The drained wreck
bears the scars of
this incredible clash.

The impact cleanly
slices off the rear end,

Leaving the fragment intact.

It sinks to the bottom,

Followed quickly
by the crippled u-boat.

Mccartney: As the
submarine was sinking
the patrol boat that,

That had rammed it
could see the germans

Inside the submarine so
we know it was opened right up.

Narrator: The german's
have been wreaking havoc in
the irish sea for months.

But now u-87's crew
meets its own terrible fate.

Delgado: Submarines
were known to their crews
sometimes as steel coffins.

I think it's an
apt analogy because when
we find one of these,

Sitting on the bottom,

Particularly
one lost in combat,

You realize that the
crew is still inside.

Narrator: The wreck
of u-87 reveals that new
technology plus some luck

And courage could
defeat a u-boat.

And by the end of 1917,

The royal navy has a
new a force dedicated
to the fight.

Mccartney: The
anti-submarine division

Is charged with
looking at every single
means of technology,

Every single means of
strategy available to it,

To combat this threat and
it develops a whole raft of

Different ways of
dealing with it.

Narrator: The counter
attack means taking the
war to the u-boats both

Above and below the waves.

Delgado: They also develop
the undersea mine as
a more effective weapon and

Ultimately build a,

A fortress wall,
a barrage as they call it,

Of mines to keep the
germans from approaching.

Narrator: Around
british coasts huge forests
of deadly floating bombs

Now protect shipping.

These massive mine
fields sink u-boats
and deter attacks.

By the middle of 1918 the
kill rate drops off from its
peak at 800,000 tons per month,

To under 400,000 tons
but that's still a
lot of sunken ships.

Delgado: For all of the
work being done to counter
the german u-boats,

They reign supreme.

Narrator: Conventional
weapons are still not
landing a decisive blow.

The british must use a secret
stealth weapon of their own.

Narrator: The english
channel is where the battle
to defeat the u-boats

Reaches its climax.

By 1918 its entrance
blocked by a huge minefield.

But off plymouth sonar scans
reveal the outline of a wreck.

It's similar to apapa,
a cargo ship.

Does this mean
that despite all allied
counter-measures u-boats

Still threaten in these waters?

Historical wreck researcher
steve mortimer is heading
out to take a closer look.

For over 4 years he's been
searching for a lost legend.

And this wreck is exactly
what he's looking for.

Mortimer: Today we're
looking to dive a shipwreck
that was sunk in 1918

After a battle
with a german u-boat.

We've been looking for
her for a number of years,

Today we've got
a really hot target.

She's lying in 65 meters,
we think, something like that.

All we can do is go down,

See what we find, and
see if we can identify her.

Narrator: Among the
thousands of defenseless
cargo ships sunk by u-boats

In these deadly waters,
steve's target is special.

The shape and
size of the hull,

Proof that this was
built as a cargo ship.

And the mangled
wreckage shows that
it met a violent end.

But the murky conditions
obscure further secrets.

Only draining away
the english channel can
fully uncover the wreck.

And reveal the
extraordinary truth.

The hull is twisted and bent.

The bow torn open.

Classic torpedo damage.

But there's a totally
unexpected discovery too.

Naval guns.

Military hardware
on a cargo ship.

For steve mortimer it's
the evidence he's dreamed of.

Mortimer: Fantastic!

That must be it,
that must be it!

The engine's on the
stern of the ship,

There's two big
guns on the stern.

It can't be anything else.

That must be hms stock force.

Narrator:
Stock force is a legendary
british secret weapon.

Codenamed a 'q' ship.

Delgado: The q-ship
is a warship disguised
as a merchant vessel.

Mccartney: It is a ship
that is trying to pretend
to be something it isn't,

And in this particular case,

To look innocent,
but it is in fact
far from innocent.

Narrator:
She may look like
a harmless cargo ship,

But stock force
is heavily armed.

Four-inch naval guns,

Like those on a cruiser
or destroyer sit on platforms

That can be folded away
and hidden below deck.

Grove: It's one type of
stealth against another
type of stealth.

Narrator: Under a
directive from admiralty
chief winston churchill,

The royal navy has

Deployed q ships since the
submarine menace first began.

Mccartney: It's thought to
have been at least 200 ships
and they vary from the very

Smallest little fishing vessels,

Even single
mast sailing ships,

Right through to
large merchant ships.

Narrator:
The sailors on board
are not merchant seamen,

They're fighting men,

Practiced in the
art of deception.

July 30th 1918.

As stock force sails
along the english channel,

Her job isn't to
transport cargo,

But to lure
a u-boat to attack.

She spots a periscope.

The trap can be laid.

What happens next
makes stock force
and her crew famous.

Their story immortalized
in a silent movie.

With great skill u-80 has
crept through a minefield
and strikes first.

Mortimer: Most of the
bridge is destroyed.

Some members of the
crew are trapped.

Narrator:
Stock force starts to sink.

The crew rushes
to abandon ship.

But it's all
part of the trick.

Mccartney: They
were even trained how
to tip the lifeboat over

While they
were dropping it,

So just to make the whole
thing look very amateurish.

The crew would then be
off and the u-boat would
then move in to close

Quarters to
finish off the ship.

Narrator:
U-80 takes the bait,

Surfacing to inspect
its handiwork.

Stock force's captain
harold auten holds his nerve.

Mortimer: Auten waits
until the u-boat is in the
optimum position to attack it

And then shouts,

"let's go", ordering
his crew to fight back
with everything they've got.

Grove: In would
come the submarine,

Down would come the
covers over the guns and

Battle would commence.

Mccartney: It would be
a hell-fire of shells
pouring into it.

Grove: You have to be able
to hold your nerve even
if your ship is sinking.

And open fire
and continue firing on
a platform that is going

Glug, glug,
glug into the ocean.

Narrator: The u-boat is hit,

The captain of stock force
escapes only moments before

His ship goes down.

Commander harold auten
wins the victoria cross.

Britain's highest
award for valor.

At last the allies
are neutralizing
the u-boat threat.

And cargo ships now
reach britain in well
protected cooys.

There are simply
not enough u-boats left to
stop the flow of supplies.

Delgado: If the germans
had been able to keep
producing more submarines,

They might very well
have won the war.

Narrator: When the
exhausted germans finally
surrender in November 1918,

They are forced to
hand over their u-boats.

Mccartney: Before 1914,
there isn't a great deal
of understanding about

What the submarine
can really do.

But by 1918,

Everybody knows,
it's a lethal weapon.

Narrator: No-one knows
this better than the man

Bent on resurrecting
german naval
power in the 1930s.

Delgado: The nazis,

Well aware of the
success of the u-boats
in world war I,

Adopt that technology
and adopt those
strategies yet again.

Narrator: In
the second world war,

The nazis launch over 1100
new and improved u-boats.

And once again they
devastate allied shipping.

Crewed by brave
and remorseless men,

The killer u-boats
revolutionize naval warfare.

The ancestors
of the super-subs
that silently and secretly

Dominate the oceans today.

Captioned by cotter
captioning services.