Nazi submarine which sank off the coast of North Carolina 72 years ago has been pictured for the first time, showing how the vessel has remained as a remarkably intact tomb for the 45 sailors onboard.
The U-boat, U-576, had been dispatched to the American coast to hunt Allied cargo ships.
Captained by Hans-Dieter Heinicke, it had been damaged during its months of activity in the Atlantic. And the submarine was limping home to Germany when, on July 15, 1942, it spotted a convoy of 24 ships.
Among them was the Bluefields, a merchant tanker flying the Nicaraguan flag, and headed from Virginia to Florida.
Heinicke, 29, had managed to sink three ships during his four prior patrols. One of his victims, the armed British freighter Empire Spring, had sunk off Nova Scotia, killing all 55 mariners aboard.
Another, the Norwegian vessel Taborfjell, sank off Cape Cod so fast that only three of its 20-man crew survived.
In the case of the American freighter Pipestone County, torpedoed off Cape Henry, Virginia, in April 1942, Heinicke surfaced near the lifeboats and gave the survivors provisions. He apologised for sinking their ship, and no one was killed.
But, three months later, on seeing the 24 vessels approaching, he was determined to attack – despite the convoy being protected by aircraft.
“In spite of his damaged ship, Heinicke decided to attack at all costs,” a report held by the Monitor National Marine Sanctuary reads. “However, at 4pm, just before he could fire his torpedoes, one of the Coast Guard cutters picked up a sonar contact.”
Three depth charges were dropped immediately, followed by five more.
Heinicke fired four torpedoes, sinking the Bluefields – whose crew all survived – and damaging two more ships.
But his submarine sank, taking with it all 45 people on board.
“It’s sort of unreal,” said Joe Hoyt, NOAA maritime archaeologist and the chief investigator on the project, who was among the first to glimpse the boat on August 24.
“I knew the story, but the moment that we get in there and it comes out of the gloom at you – it was humbling,” he told The Washington Post.
“One of the things we’re looking for is what happened to the crew.
“Did they try to get out the escape hatches? Did the ship flood catastrophically? Were they on the seabed for some period of time, disabled with air still in the sub?
“There’s 45 guys inside of that thing.
“And no matter the exact circumstances of their demise, it had to just be horrifying.”
Both the Bluefields and the U-576 were found in August 2014, lying 721 feet beneath sea level, a few hundred metres apart. They are considered war graves, and are unlikely to be removed. The German submarine remains the property of Germany.
The National Oceanic and Atmospheric Administration (NOAA) had been searching for the sub since 2009, and eventually found it using sonar.
German subs sank 600 ships off the coast, often so close to the shore that they could use the glow from US towns to backlight their targets at night.
The busy shipping lanes off Cape Hatteras, North Carolina, were so heavily targeted that the area became known as Torpedo Junction, and over 1,600 seamen lost their lives.
The toll was high among Germans, too.
Ed Offley, whose book The Burning Shore details the battles off the US coast, calculates that 75 per cent of German U-boat crewmen involved in the Battle of the Atlantic’s North American campaign perished at sea.