Sirens blare as valves purge air and two submarines descend into the depths of the ocean.
Sailors sprint through the narrow corridors of the submersible, turning valves and reloading
torpedoes into spent tubes.
As the submarines dive deeper the The HMS Venturer releases a final barrage of torpedoes-
they all miss... except one.
Over the hydrophone the sound of an explosion and the twisting of steel can be heard.
The first, and only, underwater submarine battle is over.
A mangled German U-boat sinks into the depths of the ocean.
In 1944 the Germans launched Operation Caesar.
It was a last ditch effort to buy the Axis Powers more time to turn the war around.
They were in deep trouble as Allied forces closed in on all fronts.
Germany hoped that they could sneak advanced technology to Japan using a submarine classified
as U-864.
This would allow Japan to continue the fight in the Pacific, hopefully drawing Allied forces
away from the collapsing Axis armies.
The Nazis loaded advanced weapon designs such as schematics and parts for the Jumo 004 turbojet,
and guidance components for V-2 ballistic missiles onto U-864.
The U-boat was just under 300 feet long and designed to carry large cargo shipments long
distances.
U-864 was also loaded with massive amounts of liquid mercury, which was used for manufacturing
explosive primers.
The crew was briefed on their mission, German and Japanese scientists were loaded onto the
U-boat, and on December 5, 1944 Captain Ral-Reimar Wolfram launched U-864 and proceeded towards
the Arctic.
His path was laid out to sneak past the Soviet Union undetected, and deliver the cargo to
Japan.
But from the beginning the mission seemed to be doomed.
U-864 proceeded north.
Allied forces patrolled most of the waters in the area, so Wolfram knew he needed to
travel as stealthy as possible.
To do this he would need to take risks, and move into more dangerous waters.
In order to have Axis protection for as long as possible U-864 sailed along the coast of
Northern Europe where air support remained in range.
As the U-boat made its way through the shallow waters, disaster struck.
Wolfram grounded the sub while trying to pass through the Kiel Canal.
The jagged rocks tour into the hull of the submarine.
The crew had to assess the damage, and once inventory was taken, Wolfram had no choice
but to turn the submarine around and return to drydock for repairs.
The treacherous journey around the arctic would require everything to be working perfectly,
and until the U-boat was repaired, it had no shot of making it all the way to Japan.
U-864 stealthy made its way to Bergen, Norway, which was still controlled by Axis powers.
As the submarine was being repaired Allied forces launched a bombing run into Norway.
They weren’t aiming for U-864, but the dry dock where the U-boat was being repaired was
a target.
The British planes roared over the Axis base.
Anti-aircraft guns fired their cannons into the sky, trying to take out the bombers before
they could drop their payloads.
Most of the bombers made it to their target and dropped a series of “Tallboy” and
“Grand Slam” earthquake bombs around the drydock.
The bombs were specifically designed to penetrate the surface and detonate below ground to send
the explosion’s full force through the bedrock.
The result was the destruction of underground structures like submarine pens and bunkers.
Unfortunately for U-864, it was in the submarine pen when the detonations occurred, causing
even more damage to the U-boat.
This led to further delays in Operation Caesar and the mission to deliver the cargo to Japan.
The numerous delays for repairs would culminate in the only underwater submarine battle in
history.
Unknown to the Germans, the British had cracked their codes.
The Allies intercepted a communication about U-864’s mission and knew that they couldn’t
let the Nazi sub make it to Japan.
They immediately dispatched the HMS Venturer to destroy the U-boat.
The Venturer was almost twice as fast as the bulky U-864, but it was also much smaller.
It had a limited crew and could fire four torpedoes at once, but only held a relatively
small number of torpedoes on board compared to U-864’s arsonal of 22 torpedoes.
This meant that the Venturer needed to make every shot count.
The Venturer left for its mission under the command of Lieutenant James S. Launders on
February 6, 1945.
The plan was to intercept U-864 off the coast of Norway.
Launders had sunk 13 vessels during the war including a German submarine that had surfaced.
The problem that Launders faced now was finding the exact location of U-864.
He knew the general vicinity, but the vastness of the ocean, and the technological challenges
of locating a submerged submarine without giving his position away, made his mission
incredibly difficult.
The main method the Venturer had to locate U-864 was the use of hydrophones.
This device could listen for sounds of enemy submarines underwater.
However, it was only effective at a limited range, and there was a lot of ocean to cover.
The other way the Venturer could locate an enemy submarine was through active sonar.
By sending out an acoustic wave and waiting for it to bounce off an enemy sub, the location
of the vessel could be obtained.
However, the problem with active sonar was that it also alerted the enemy of the location
of the Venturer.
The Venturer reached the coordinates where U-864 was supposed to be located.
They scoured the area for any signs of the German U-boat, but came up empty.
Unfortunately for the Venturer U-864 had already passed through their location, and was now
out of range of the hydrophones aboard the British submarine.
Launders had missed his chance; the Nazi U-boat was on its way to Japan.
However, U-864’s bad luck was not over yet.
The U-boat’s diesel engine began to misfire, causing the vessel to slow down.
Wolfram was forced to make another difficult decision; either he pressed forward, which
was a huge risk, or returned to drydock for additional repairs.
Again Wolfram knew the long journey through the Arctic would be brutal, and if anything
happened to the engine while in the icy cold region, he and his entire crew would perish.
So, Wolfram decided to turn around and head back to Norway.
Wolfram had no way of knowing he was headed right into the Venturer’s trap.
It was only out of sheer bad luck that the failing diesel engine aboard U-864 caused
the U-boat to turn around and head straight towards Launders and his vessel.
The crew of the Venturer were monitoring the area even though they had almost completely
given up hope of ever locating the German U-boat.
Then one of the crew picked up something on the hydrophones.
It was the misfiring diesel engine of U-864.
The alarm was sounded and the crew prepared for the chase.
The Venturer stealthy moved towards the sound of the misfiring engine of the U-864.
Then Launders saw what he suspected was the periscope or snorkel mast sticking out of
the water.
The snorkel mast allowed submarines to travel just under the surface of the ocean, and still
pump the oxygen the diesel engine needed into the vessel.
The Venturer had located its target.
The diesel engines were turned off so the submarine could run silently underwater on
battery power.
Launders waited for the U-boat to surface so he could take his shot.
Unfortunately, U-864 could stay just below the surface of the water using its snorkel
for the duration of its journey back to port.
Then the U-boat did something strange.
It began zigzagging from side to side.
Launders knew the Germans must have either suspected they were being pursued, or had
already detected his submarine.
The chase continued for hours.
U-864 refused to surface, and began taking even more drastic evasive actions.
This alerted Launders that the Germans were now fully aware that they were being followed.
The Venturer’s batteries were running low and the submarine would soon need to surface
itself, which would leave it vulnerable to attack by the German U-boat.
Launders gave the command to arm all torpedoes.
The captain calculated the trajectory and depth of the U-boat with the limited data
he had.
The order to fire blared across the speakers of the torpedo bays.
The Venturer “ripple-fired” four torpedoes, with each being launched about 18 seconds
apart.
The second two torpedoes were fired at a lower depth, just in case the enemy dove deeper.
Launders ordered the Venturer to immediately dive in case of a counterattack.
As the sub descended into the blackness of the ocean the crew waited with anticipation.
Time seemed to freeze as everyone on the Venturer held their breath, waiting for the hydrophone
operator to confirm a hit.
There was no explosion.
It seemed as if all of the torpedoes had missed.
Hope began to leave the crew of the Venturer.
Then, suddenly, the hydrophone operator perked up.
The sound of an impact, explosion, and the tearing apart of iron could be heard over
the headset.
U-864’s hull ripped open and the entire vessel collapsed in on itself from the massive
pressure of the ocean.
The last torpedo fired had found its target.
The handphone operator waited patiently until he heard the enemy U-boat thud against the
bottom of the sea floor.
All 73 people on board U-864 were lost to the ocean.
The Axis Powers’ hopes of delivering weapons and materials to Japan sank with German submarine.
The site of the wreck remained undisturbed for over 50 years until the Norwegian Navy
located it.
U-864 was lying in a crumpled heap on the bottom of the ocean, but its cargo of Mercury
was leaking out of the vessel and into the water.
Also, the U-boat still had unexploded ordinance within its hull.
In order to stop the leak, and prevent any accidental explosions, the Norewegian authorities
decided to cover the wreck under 160,000 tons of sand and rock.
The battle between U-864 and the Venturer was the only underwater submarine battle in
history: but why?
Submarines had been used as far back as 1776 during the American Revolutionary War with
the submersible known as Turtle.
How is it possible that there was only one underwater submarine battle?
There are a few reasons.
World War II was the height of submarine warfare.
After the war ended submarines were still used, but normally only for moving cargo and
as support.
During World War II submarines needed to spend most of their time on the surface, so their
diesel engines could get the air they needed.
This meant that submarine warfare often took place on the surface and not underwater.
Also, before and during World War II when submarines were underwater there was no accurate
way to gauge exactly where the enemy was in three dimensional space.
Lastly, torpedoes at the time were designed to float up to the surface to strike ships,
so firing a torpedo at an underwater target was not ideal.
This is not to say that other submarine engagements didn’t occur, just that underwater battles
were incredibly rare because of these limitations.
Today submarines are equipped with radar and guided torpedoes that would make underwater
battles possible, but no wars are currently being fought under the waves of our oceans.
This all shows that what the Venturer did by destroying U-864 underwater was incredibly
impressive.
It also happened due to a considerable amount of luck.
The torpedoes fired by the Venturer were more or less shot blindly into the ocean abyss,
and the fact that one of them impacted U-864 was nothing short of a miracle.
Now check out “50 Insane Submarine Facts That WIll Shock You.”
Or watch “Why Living On A Submarine Sucks.”