Original subtitles

January 1942

America is just weeks into World War II

when the European fight comes to our shores

Hitler's U-boats waste no time going on the attack

They brought the war to us

in a way that caught us by surprise

The attacks are devastating

Thousands of lives lost,

more ships sunk than at Pearl Harbor,

and Nazi spies secretly delivered to American soil

They kicked our asses,

and yet we were getting no payback

A lot of Americans have forgotten

how close the war came to our shores

and how close it was to our homes

Now renowned explorer Robert Ballard and his team

are returning to this forgotten battlefield

with the latest technology

Okay team, 100 meters

Here, we're able to get a picture

that shows you what it would like

if you could take the water away

Their work will help rewrite this chapter of World War II

and bring closure to a 73-year-old mystery:

who sank German U-boat U-166?

How close did the Nazis come to victory in the Atlantic?

Right now, on this NOVA/ National Geographic special

The Gulf of Mexico, 120 miles off the coast of New Orleans

These peaceful waters were once the setting

for a violent, little-known chapter of World War II

Deep below the surface lie the remnants

of a devastating Nazi attack on America: Operation Drumbeat

Just after the US entered World War II,

Hitler's submarines, the deadly U-boats,

struck hard and fast up and down the East Coast

They hunted down and sank the vulnerable cargo ships

that were critical to the Allied war effort

And they took the war further, extending their assault

all the way into the Gulf of Mexico

Now, explorer Robert Ballard and his crew

prepare to investigate this battlefield

To reach the sea floor,

they'll use high-tech remotely operated vehicles... ROVs

The beauty of the ROVs,

these vehicles can stay down for days and days and days

Square up on the target and drive over to it

The ROVs descend one mile beneath the surface,

where the casualties of the Nazi assault still rest

A World War II-era cargo ship, the Alcoa Puritan

In 1942, she hauled aluminum ore

vital to America's wartime factories

Her scars are still vivid

That's a hole, that's a shell hole

So if you could stop laterally and go in and frame that

These are bent inward

Yeah, you can tell it went in

Yep

Joining Ballard is wreck diver Richie Kohler

He's spent decades studying and diving on sunken U-boats

This wreck is a snapshot

of when the U-boats first came to America

This is when the U-boats were not afraid of us

We hadn't got our act together

Not far from the Alcoa,

an oil tanker, the SS Gulf Penn,

90,000 barrels of oil still trapped inside

These are in some ways ticking time bombs

in the sense that the hull will rupture

and you'll have oil come out

Could you look at that wreckage?

Could you look at the wreckage before you go too far?

But Ballard and Kohler's ultimate goal

is a pair of shipwrecks resting not far away,

one the hunter, the other hunted

This is the SS Robert E. Lee, the victim

In 1942, 407 souls walked these decks

On board the Robert E. Lee was not only passengers,

but there were actually survivors

from previous German U-Boat sinkings

that occurred out in the Atlantic Ocean

Square on the gun a little better

A three-inch deck gun had been added for protection

against the U-boat threat

This gun never went into play

They never had a target

He's locked up, he's in a stored position

The attack came with almost no warning

You could almost imagine them standing along the side

looking at what they thought was a porpoise

and then it makes a turn and comes into them

It's actually a torpedo

Today, the fatal wound inflicted by the German torpedo

is hidden beneath layers of silt on the ocean floor

It's amazing that most of the damage is not visible

Now, we're looking at a ghost ship

I mean, it's obvious that it was abandoned

We can see where the four lifeboat davits were swung out

Within five minutes,

these people were in the water fighting for their lives

Just over one mile away, the attacker:

German U-boat U-166

Missing for 59 years,

her rusting hull was spotted in May 2001

during survey work for a new underwater pipeline

But how did U-166 sink?

Who was responsible?

And why is she lying so close to her victim?

The official record offers little clue

For decades, the circumstances of this U-boat's sinking

have been mired in controversy

In 1942, a young destroyer captain,

commander Herbert Claudius, claimed credit for the kill

But the official report said Claudius botched the attack

It was one man's word against the US Navy

in a case obscured by the fog of war

Ballard and his team believe their technology,

building on the earlier survey work,

can finally put the question to rest

It isn't until fairly recently

that this submarine's been found

I'm gonna use my technology,

and see if an injustice was done that needs to be corrected

It's a story that began three years before U-166 was sunk,

before America had even entered the war,

when Great Britain found itself facing off against Nazi Germany

in one of the most pivotal conflicts of World War II:

the Battle of the Atlantic

Lasting from the first day of the war to the very end,

the fighting would ultimately claim

nearly 6,000 Allied and German ships

and span 5,000 miles of ocean

What was at stake was simply Allied survival in World War II

Now at this stage of the war,

England was standing alone against the rest of Europe,

which had been conquered and brought under Nazi tyranny

If the British were defeated, the war would be all but lost

There was no way that the Allies

were going to be able to invade Normandy

from Hoboken, New Jersey

It just wouldn't have worked

You needed a launch pad; the launch pad was England

But as an island nation, Britain was vulnerable

Its survival depended on supplies imported from abroad:

raw materials, food, weapons

Roughly one million tons of cargo a year,

crossing the Atlantic

By 1941, the Nazis were close to cutting off that flow

The key to their success was the Unterseeboot...

German for "underwater boat"...

Known to the rest of the world as the U-boat

The Nazis built nearly 1,200 of these deadly machines

They were meant for one purpose only:

to attack

At either end of the U-boat

were tubes for launching torpedoes...

23-foot-long underwater missiles

At its center, the conning tower

Below it, a maze of controls

for steering, diving, and surfacing

Submerged, a U-boat's survival depended on its pressure hull

Invisible from outside,

these structural ribs and steel plate

were all that stood between the crew

and thousands of tons of seawater

Like today's hybrid cars,

U-boats relied on a combination of internal combustion engines

and battery-powered electric motors for propulsion

On the surface, air-breathing diesels

could drive up to 18 knots, roughly 20 miles an hour

Underwater, the electric motors took over,

but the batteries were a critical vulnerability

They typically lasted less than 24 hours,

and the diesel engines

could only recharge them on the surface

A U-boat is ultimately

a submersible rather than a true submarine

It's not intended to operate perpetually beneath the water

They have to be on the surface several hours every day

in order to recharge their batteries

And a U-boat on the surface was a target

Despite this weakness,

the U-boats were stunningly effective

The U-boat was a terrifying weapon of war,

and it was especially terrifying when it took on unarmed ships

that were carrying cargo

Commanding the German assault

was Kriegesmarine admiral Karl Dönitz

During World War I he commanded a German U-boat

That's where he learns a lot of his lessons

He could be harsh at times,

but the U-boat men considered him

a just leader,

and that's why they followed him all through the war

With the US still neutral,

Dönitz focused his fleet on the British ships

Wolfpacks, groups of U-boats

ranging from three to more than 20 subs,

swarmed and overwhelmed the British convoys

Dönitz directed the Wolfpacks himself via long range radio

Admiral Dönitz was a very hands-on type of manager

He wanted to know where his U-boats were at all times

He required them to call in on a daily basis

The Allies could hear the transmissions,

but they couldn't understand them

The Germans had a secret weapon:

the code machine known as Enigma

The Enigma machine itself

looks like a very elaborate typewriter

that encodes and decrypts the messages

as they're sent and received

The secret of the Enigma machine

was its constantly changing code

With every keystroke,

the code rotors that scrambled the message shifted slightly,

generating a new code

No word would ever be encoded the same way twice

Every day, the sender and receiver

set the rotors to a position

listed in codebooks each operator carried

The Allies had secretly copied one of the machines,

but without knowing the settings,

they had no hope of deciphering the messages

By 1941, the Enigma-equipped U-boats

were winning the Battle of the Atlantic

England was being starved into submission

In fact, British Prime Minister Winston Churchill

would later say that there was only one thing

that he feared during World War II,

and it was the U-Boat

Then, a breakthrough

In May of 1941, U-110 stopped reporting in

German command believed her sunk

In reality, she had been captured

off the coast of Iceland

Her Enigma machine and the code books

specifying the settings were shipped back to London

British mathematician Alan Turing

and a secret team of codebreakers went to work

The British were able to break the German naval ciphers

by the end of May, beginning of June, 1941

That was critical for saving British convoys

for the rest of 1941

The Germans had no idea

Mathematics, not munitions, had bought the British crucial time

Until December 7, 1941,

when the Japanese bombed Pearl Harbor and everything changed

With America officially at war,

US ships could now be targeted

Admiral Dönitz seized the opportunity

to tilt the battle back in Germany's favor

He knows that right after Pearl Harbor,

if he sends U-Boats across

to attack the US Atlantic coast,

he knows he'll get a big payoff

because the United States won't be ready

Dönitz believed his U-boats

could cut England's lifeline of vital cargo

by striking at the source

Operation Drumbeat was born

But with his U-boats stretched thin,

Dönitz had only a handful of long-range boats,

known as Type IXs, available to send to America

He assigns six Type IX U-boats, and then one of them falls out,

so it's only initially five Type IX U-boats

to operate off the US East Coast

The trip to America took three weeks

British codebreakers warned the US,

but in the wake of Pearl Harbor, the Navy had other priorities

Neither the US Navy nor the Army air forces was prepared

Not only did they not have the airplanes

and the ships available,

but the ones they did have available

did not have the sensors or weapons

that could destroy a U-boat

Even basic protective measures were ignored

You gotta remember,

all of Europe is blacked out now,

and all the lights were on

There seems to be no alerts whatsoever

Officials worried a blackout could disrupt commerce

But no blackouts meant cargo ships

were perfectly silhouetted against the bright lights

They found, in effect, U-boat Disneyland

It was wonderful

Horst von Schroeter was watch officer on U-123

We closed the shore

within, say, two or three nautical miles

We smelled the forest ashore,

and we saw the autos, the cars, running on the shoreway

Erich Topp was commander of U-552

and the third-most successful U-boat commander of the war

It was a shooting of hares

It was because the Americans at that time

had not developed counter- measures against submarines,

and so we had a very easy game there

It took one week, as I remember, only

One week all the time, and we sank, I think, about ten ships

In fact, they return to their ports

in the Bay of Biscay coast of France

empty, having fired all of their torpedoes

By February 6, barely three weeks

after the first U-boats arrived in US waters,

they'd sunk 25 ships

Spurred on by the success,

Dönitz sent every U-boat he could spare across the Atlantic,

including the newly built U-166,

the wreck Ballard is closing in on

Onboard the Nautilus, Ballard's team preps the ROVs

The primary unit, named Hercules,

is equipped with several high-definition cameras

Its sophisticated sonar will locate and map the wreck site

This technology will offer a view of the U-boat

with stunning clarity and detail

Hercules can dive as deep as 2 5 miles,

putting U-166 well within its reach

But just like human divers, it doesn't go alone

Hercules is tethered to a second ROV named Argus

Physically linked to the ship above,

Argus acts as a stabilizer and light source for Hercules

It also sends video up to the Nautilus

so the crew can watch for potential hazards

Hercules is kept on a short leash

to prevent its tether from getting tangled

Operating the ROVs like this is tricky

The ship's computers must maintain its position

directly above the wreck

so the ROVs can safely navigate the site

So computers are driving the ship

Humans aren't driving the ship right now,

it's being driven by computers

As we move the ship, we're moving Argus

And Hercules's job is to stay out on point

It will take over an hour

for the ROVs to reach the wreck of U-166

By March of 1942, Dönitz was sending

nearly half of his combat-ready U-boats to attack America

The Germans had also regained a crucial advantage,

a new Enigma machine

The German navy increasingly suspects

that their cipher machine has been compromised,

as indeed it has been

Dönitz upgraded the Enigma machines on board his U-boats

with an additional rotor

Overnight, the new machine, nicknamed Shark by the Allies,

made their codebreaking useless

From then on, the Germans were well ahead

in terms of information

because the Allies no longer could read

what the Germans were planning

For Dönitz and the U-boats, the hunting was almost too good

They kept running out of torpedoes and fuel

and had to travel 3,500 miles back home to resupply

Until German engineers came up with an inventive shortcut:

the Type XIV U-boat, dubbed the Milk Cow

The Milk Cows were not designed to fight

Instead of carrying offensive weapons,

they just carried extra fuel and provisions

and even extra torpedoes for the U-boats

With 430 tons of fuel and supplies,

the Milk Cows were floating gas stations

And the Germans had an ideal location to deploy them:

the Atlantic Gap

Aircraft based in North America,

aircraft based in Iceland or Greenland

or in the United Kingdom,

their umbrella of coverage left a gap right in the middle

That mid-Atlantic gap was an area where U-boats knew

that they could operate with impunity

because no Allied aircraft could reach that gap

The Germans seemed to hold every advantage

The U-boats were virtually unstoppable

By April of 1942, three months into Operation Drumbeat,

nearly 250 Allied ships had been lost in American waters

Not a single U-boat had been sunk

Happy times, they called it

In Germany, "Die Glückliche Zeit"

There were more targets available

than they could cope with

And the U-boat missions were only becoming bolder

In June 1942, the Nazis carried out

one of their most daring attacks on America

Known as Operation Pastorius, the program used U-boats

to land teams of Nazi spies on American soil

The overall plan was that German saboteurs and spies

would attack vital railroad bridges,

aluminum plants that were making the skin of the aircraft

that would ultimately drop bombs on German cities

And the U-boat contribution to this mission was vital

It couldn't have been done without them

Two teams of spies were landed, one on Long Island, New York,

the other near Jacksonville, Florida

The spies dispersed into the civilian population

and began their preparations

Meanwhile, Dönitz and the U-boats

kept probing American defenses

They soon identified an enticing new weak spot:

the shipping lanes in the Gulf of Mexico

We had lapsed into the thinking

that everything's fine in the Gulf of Mexico

because the enemy is not there

And so Dönitz sends them into the Gulf of Mexico,

realizing that he'll get yet another big payoff

with the Gulf of Mexico,

and oh, God, what a payoff he got

In the month of May 1942, he sank 41 ships

That's more than one ship a day

going down in flames in the Gulf of Mexico

It was to this hunting ground that U-166 would be assigned

for her first patrol in America

Home movies recorded by U-166's captain, Hans-Gunther Kuhlmann,

show the young crew training just weeks before the mission

On June 17, 1942, they left port and set course for America

They would never be seen again

There's bottom

There you go

Aboard the Nautilus,

Bob Ballard is trying to understand their final moments

What's it say?

Target bearing?

Target bearing is two thirty

Yeah, so it should show up on sonar

They're coming down close enough

After reaching American waters in July of 1942,

U-166 quickly sank three ships

and was looking for more off the coast of Louisiana

On the afternoon of July 30,

another target appeared in her sights:

the Robert E. Lee, making its way to New Orleans

U-166 launched a single torpedo

The passenger ship never fired a shot in return

Within minutes, it was sunk

But what U-166 didn't realize

was that the Robert E. Lee was not alone

She had a naval escort ship, PC-566

Its captain was a young naval officer,

Herbert Gordon Claudius

He was a farm boy from Nebraska,

and he, I guess, wanted to get out of Nebraska

And then of course,

his first ship in the Navy was the PC-566

PC-566 had been commissioned only the month before

Claudius and his crew

were about to see combat for the very first time

As soon as a German torpedo struck Robert E. Lee,

Claudius swings the PC-566 into action

One of the men on deck of PC-566

observes a periscope in the water

Claudius then turns the vessel toward that periscope sighting

He's doing that in an attempt to approach from its blind side

A U-boat's periscope has a narrow field of view

With the U-166's lens pointed at the sinking Robert E. Lee,

the German captain couldn't see the Navy ship coming

He's in the fray right now

He's trying to kill this guy

He wants to sneak right up on top of that guy

so he can't get away

He's bearing down on it as fast as he can,

and when he's 120 yards away, he sees the periscope retract

He's following the wake,

and directly over the estimated position,

he's setting off a sequential series of five depth charges

The depth charge is an underwater bomb

and the Allies' primary weapon against U-boats

The attacking ship estimates the location

and depth of the U-boat,

then sets the charges to detonate

when they hit that depth

Fire two

Fire two

Water pressure triggers the explosion,

sending a shockwave ripping through the ocean

The explosion isn't powerful enough to blow up a U-boat

The idea is to simply crack its pressure hull

then let thousands of tons of seawater finish the job

But depth charges aren't necessarily a death sentence

The shock wave is only dangerous up close

If the U-boat can dive out of range, she can escape

U-boat crews had a series of carefully rehearsed procedures

for trying to elude depth charges,

as shown in this actual wartime footage

The bow planes were set to maximum angle,

driving the boat deeper

The electric motors were set to full power

Men who were not on duty ran forward

Their weight helped point the boat down

The emergency dive

was the most critical test a U-boat crew could face

Seconds meant the difference between life and death

Horst von Schroeter was watch officer

on one of the first U-boats in Drumbeat, U-123

From the order alarm,

it took 30 seconds to disappear from the surface

and another 30 seconds to be on a depth of 60 meters

30 seconds can be a long time in war

Werner Hirschmann was chief engineer on U-190

I would call anybody

who was not scared for his life under those circumstance a liar,

because it is a scary experience

to hear a depth charge dropping into the water

and then expect, in about five or ten seconds,

an explosion to go off

There's nothing you can do

You can just sit there and wait,

and this period of lack of activity is really unnerving

The crew of U-166 left no record of their final moments

They didn't send a radio report that day,

or even a distress signal

All that is known comes from the report filed by Claudius

He dropped a second round of depth charges

An oil slick spread on the surface

So now the periscope's no longer visible,

the depth charges have gone off, there's no wake

You know, did he kill it?

And he sees an oil slick

You know, that's a very good indication that he hit it

In his report, Claudius was clear

It is my opinion that the sub was sunk

or so mortally wounded that she would never return to her base

I mean, this is the fog of war

But he is pretty confident that that oil slick

is associated with that submarine

They attack the submarine

They come back and rescue the survivors,

the 400 people that are in the water from the Robert E. Lee.

Claudius radioed for help,

knowing that his ship was too small to rescue everyone

It's not that big a ship

It was so top heavy

that he actually had to unload some of them back into lifeboats

so that his ship became stable

But then two other ships came out

and between the three boats,

they took them back to New Orleans

Claudius returned to port with the survivors

Then, a shock

Instead of getting a hero's welcome,

he was actually reprimanded

His entire attack is criticized

As a matter of fact,

he's removed from command and then sent back to school

They didn't believe, not for one minute,

that he had actually sunk the U-166

Senior commanders concluded that Claudius

made a series of basic errors

They said he was in the wrong position

while escorting the Robert E. Lee;

he approached the U-boat the wrong way;

and crucially, he deployed his depth charges too slowly

and at the wrong depths

They're all saying, "No way

"No way did he sink this sub

"The attack was poorly conducted,

"and there is insufficient evidence

to give higher assessment than an F"

An F!

Says "F" right there

Flunked

That's pretty humiliating

Gordon Claudius, Herbert's son,

was only two years old at the time

He believes the review of his father was unfair

It was not favorable

He didn't talk much about well, his wartime activities

My sister, she was older than I was

and more in a position to think about things and ask questions,

and she said, well, she asked him one time

and all he said was, well, he attacked a submarine

and he saw an oil slick and he saw debris

That was it

I think it not only got to my father,

but I think it got to the whole crew

After the war, captured German records

revealed that U-166 was the only U-boat lost in the Gulf

But the Navy concluded that U-166 had been sunk

in an entirely different attack that took place two days later

and 140 miles from where commander Claudius gave chase

A U-boat is spotted

south of Houma, Louisiana, running on the surface

And a US Coast Guard patrol plane

attacks it with depth charges,

and then in the aftermath of the attack

observes an oil slick on the surface of the water

The Coast Guard air crew was given credit for the kill,

and so official history was written

Yet despite decades of searching,

a wrecked U-boat was never found at the location

where the Coast Guard plane made its attack

It's not for a lack of trying

People are going out on dive expeditions

thinking that they have the exact spot

where U-166 went down, but nobody finds it

Until 2001, when marine archaelogists

from C&C Technologies made a surprising discovery

during preparations for an undersea pipeline

When we were looking at

the extra data and we saw the bow section

And at that point we looked at each other and we were like

All the pieces came together

And it turns out it was the U-166

We knew in that moment

that Lt Commander Claudius and the crew of PC-566

had sank U-166

Yet 13 years later,

the Navy record still denies Claudius credit

So now we need to set the record straight,

because this guy died without recognition for what he did

Unless Bob Ballard and Richie Kohler can find a way

to prove to the Navy that Claudius was responsible,

the official record will stand as is

A mile below,

Ballard's ROVs are closing in on the wrecked U-boat

All right, showtime

Let's drop down there

There it is

Thar she blows

She is in incredible condition,

right where the previous survey said she would be

The aft part of the submarine looks like we could

just blow off the dust, start the engines and go

Right

250 feet long, weighing 1,100 tons,

in 1942, U-166 was

a state-of-the-art killing machine

Now she is a tomb

Oh, my gosh

That's a gun

So far, no damage is apparent

Back up a little

Frame it a little

Right there, okay

Though Richie Kohler sees evidence

that the crew of U-166 knew they were in danger

There is a couple of telltale signs

that this sub was in a crash dive

or trying to get down real quick

Number one, the aerial,

the antenna that you see that's bent,

that's a transmitting antenna

So it wasn't making

It's supposed to be retracted when they're diving

So he was too busy to do that?

Everything stopped

We've got the 20 millimeter gun

that should have been locked in position for underwater travel

It's swung out to port

The periscope never came back down all the way

You can almost, you know, see these men

are running to the forward end of the submarine

trying to get the bow heavier, trying to get it down,

because they knew trouble was coming

And they didn't make it

They didn't make it

It does appear the sub was running for its life

But so far, they see no sign

of the tell-tale fractures in the hull

that two rounds of depth charges should have produced

The wreck seems surprisingly intact

And then, something strange

Now, that's not normal

Could you stop right there, Will, and zoom in on that?

Ballard zooms in, looking for the bow,

the front of the sub

It appears to be buried in the sand, but it's not

It's completely gone

There's no way a depth charge

could have sheared off the bow of U-166 like this

So what happened?

The missing bow holds vital clues

We gotta go find the other piece

The ROVs move out across the sand

For many meters, there's nothing

Then suddenly

It's the missing bow

And it's been reduced to scrap metal

This is definitely not a depth charge

If that was a depth charge,

we would not see this thin lattice work

This would've been totally blown away

Normally, a depth charge just cracks the pressure hull

But this is no fracture; it's an amputation

Most of the time,

we see concave indents from depth charges

We don't see twisted and torn metal

With this level of destruction,

it makes it difficult to ascertain what caused what

It's a conundrum

The location supports Claudius's claim that he sank this boat,

but the damage doesn't match a normal depth charge attack

like the one Claudius made

To understand what happened,

the team needs to put the two pieces of U-166 back together

We know that we've got this up in the bow, separated,

and then we don't know how much

Well, you know, we take the two pieces

and we see how much of it we see

Put them together and you see what you're missing

But the visibility is too murky

to image the entire wreck in one shot

We can't see very far underwater

I mean, if you're lucky you can see 30, 40 feet

Fortunately, Ballard's ROVs are equipped

for just such conditions

What we'll do now is

we've now outlined, and so we need to bring Clara up

Is Clara in the ready?

So we can digitize this whole thing

Clara Smart is the team's high resolution mapping specialist

As she watches, the ROV does a sweep of the wreck,

taking thousands of close-up photographs

with its ultra-high resolution cameras

The vehicle takes one image every three seconds,

and what we're going to do is

we're going to combine all these images to create

One

One very big, beautiful image

You can see it's marching along

Yep, and it's just matching one picture to the next

The whole idea overall is when we are on a site,

we have a flashlight in a hay field

and you can't see anything,

but once we make these maps,

all of a sudden, like all the lights came on

so we truly see exactly what's down there

Clara will spend the next several months

stitching the thousands of close-ups

into a single giant wide shot,

called a photo mosaic, that shows the entire wreck

Every rivet and crack will be visible with unmatched clarity

Here, we're able to get a picture

you can't get any other way,

a map that shows you what it would look like

if you could take the water away

And that'll help tell us what happened to the submarine

Back at the University of Rhode Island, Clara gets to work

To start, computers assemble the images

But they can only do so much

As you can see, we've got some issues

In problem areas,

Clara will have to match individual frames by eye

It's a laborious process

Finally, Ballard calls Richie Kohler

and historian Marty Morgan to his lab

The mosaic of U-166 is complete

Thousands of photographs have been seamlessly meshed together

But will the mosaic give the team what they need?

We took about 2,000 images

with the ROV,

and that's been boiled down to these two mosaics

So this is really CSI

We're talking about 2,000 pictures

to give us one continuous image

of what the U-166 looks like now

Right, and it would be as if you were flying over it

with an airplane and you saw an aerial view

The key evidence lies

somewhere in the break between the two pieces

That's where it all took place

The fact that this has been completely blown off

And 100 meters away

And 100 meters away

You know, the question is,

was the depth charge enough power

to literally tear off the front of a pressure hull?

It's not really been seen before

In almost every instance

So you're led to believe

that there was another culprit in the mix

When the two pieces of U-166 are slid back together,

they see that the break occurred

right at the forward torpedo room

Interesting enough,

right here, where my finger is,

is exactly where the torpedo tubes would have been loaded

You can see them clearly in the blueprints

We know they're there

But something destroyed the torpedo tubes

And there's how many torpedoes here?

There could have been four

Four on the deck, four spare reloads

Spare torpedoes were stored on the floor

of the two torpedo rooms, bow and stern

If the forward torpedoes somehow exploded

while stored inside U-166,

that could explain the incredible damage to her bow

If that is what happened, it points to an unlikely

and catastrophic chain of events

As U-166 frantically dove to escape,

Commander Herbert Claudius dropped his depth charges

So they were pretty shallow

Well, they were seen on the surface with their periscope up

This is what has led me to believe the possibility

of one of the five depth charges that were distributed by PC-566

landed on the deck there

And it carried it with 'em

Marty Morgan believes a depth charge landed

directly on top of U-166

As the sub dove to escape,

she carried the bomb down to its explosion depth,

setting off a chain reaction

that detonated her own torpedoes

That would make sense because clearly it was so instant,

he's just putting his periscope down

His dive angle isn't that great

He probably wasn't even 30 feet deep

Right, so it very conceivably landed on him, clunk,

and he carried the bomb

Carries it down with him

Hustling forward to weigh down the bow,

the crew might have run right into the exploding torpedo room

If you understand how the German submarines would dive,

one of the things they would use the crew for is ballast

They would tell the crew to run

"Everyone run to the front!"

And that's exactly where it happened

The team is convinced

While a depth charge couldn't produce the damage

seen on U-166, it could have detonated her torpedoes

Combined with the U-boat's location,

it makes a persuasive argument

Instead of being reprimanded for his attack,

Commander Herbert Claudius should have gotten a medal

Nice shot

Perfect shot, actually

Couldn't have done it better

But the team still faces a huge hurdle:

convincing the US Navy

Ballard, a former Navy commander himself,

puts their findings in writing

and forwards them to the Chief of Naval Operations,

the most senior officer in the Navy

73 years after the battle,

the Navy agrees to review the case

Though it wasn't apparent in 1942,

even as U-166 sank to the bottom,

Operation Drumbeat was already drawing to a close

The sinking of 166

This is the first time we actually,

in the Gulf of Mexico, drew blood

Didn't mean that we had taken the teeth away

from the U-boats

No, they were going to continue to sink ships,

but now it was going to cost them,

it was going to cost them dearly

Allied science and engineering

were finally beginning to turn the tide

Improved radar and high-frequency direction-finding

meant the U-boats could be detected

whenever they surfaced, even at night,

while mass production of aircraft like the B-24 Liberator

meant the Atlantic Gap

was no longer a safe haven for the Milk Cows

But the decisive stroke came with the capture of U-559

in October of 1942

What they get out of U-559 enables Allied codebreakers

to regain that insight into the new Enigma machine

with its fourth rotor

And by the end of December 1942

and certainly by the spring of 1943,

the British and Americans

can now read German U-boat signals in almost real time

The Enigma code was cracked once again

The U-boats had lost nearly all their advantages

Even the Nazi spies of Operation Pastorius,

landed via U-boat to sabotage American industry,

proved to be utter failures

All eight operatives were captured within days,

and the Germans canceled the program

Never again would U-boats rule the seas

They had failed in their stated goal:

cutting off the flow of supplies from America to England

Yet they had come dangerously close,

and the damage caused by their attacks was immense

Hitler's U-boats sank 609 ships in American-protected waters

Over three million tons of cargo never made it to Britain,

and over 5,000 lives were lost

On the German side,

out of the 743 U-boats lost in World War II,

only ten were sunk in American waters

Of those, only one was sunk in the Gulf of Mexico: U-166

But will the Navy give credit

to Commander Herbert Gordon Claudius?

At the Navy History and Heritage Command,

historians have analyzed Ballard's evidence,

as well as reports from the marine archaelogists

that first IDed U-166

The two teams are nearly lockstep in their conclusions

It was Commander Claudius and his naval escort ship PC-566

The Underwater Archaeology Branch

here at Naval History and Heritage Command

looked at the information

and confirmed that absolutely, we believe that

PC-566 did successfully attack and sink U-166

Whether it was skill, whether it was luck

or a combination of both, they were successful in the end

In 2014, 72 years after the battle,

Admiral Jonathan Greenert, chief of naval operations,

and Secretary of the Navy Ray Mabus

award Commander Herbert Claudius the Legion of Merit

Good afternoon, everybody,

and we're here to recognize and actually to honor

Lieutenant Commander Herbert G Claudius

This is really for me a story, I think, of history obviously,

but also a story of explorers, of shipmates,

of friends, of historians, and I think relentlessness

to set the record straight

Gordon Claudius,

the only surviving child of Herbert Claudius,

is here to accept the award on his father's behalf

Now, 70 years later, because of technology,

we now know that your father's after-action report

was absolutely accurate

And I think this is a good example of,

"It's never too late to set the record straight,

it's never too late to do the right thing"

So it's an honor to be here today

to present your father posthumously

with the Legion of Merit for valiant actions

during a very tough and very dangerous combat situation

On behalf of your father

Thank you

I present this to you with the V for Valor,

which means it happened in combat

It sure did

This really brings closure on a story that began

a month before I was born 73 years ago

So this is a wrap, a nice wrap

So long after the conflict, World War II is fading history

Few remember the battles Herbert Claudius

and other heroes once fought so close to our shores,

but the sunken remains are still there,

often nearer than we know,

enduring reminders of just how close the Nazis came

to setting history on a very different path