A German U-boat set off from the north coast of Germany for a routine patrol with four officers and 31 crew members on board on Jan. 13, 1915.

It was never seen again. The mysterious disappearance sparked a rumor—believed to have been started by another U-boat commander—that the submarine had washed ashore in Britain with all those on board dead, perhaps caused by a gas leak, reports the Telegraph.

After more than a century, that story has now been debunked. Offshore wind farm developers uncovered the wreckage of the U-31 sub in 100 feet of water about 55 miles off the coast of Norfolk, England.

"We looked across the maps we had and this wreck didn't appear on any of them," a member of the survey team tells ITV News.

"We knew pretty quickly that we'd found something really special." The scanning team first spotted the wreck in 2012, but marine archaeologists didn't identify it as the U-boat until now.

Divers initially suspected it was a Dutch sub that vanished in World War II. The U-boat is believed to have struck a mine and sunk. "After being on the seabed for over a century, the submarine appears to be in a remarkable condition with the conning tower present and the bows partially buried," says one of the marine archaeologists on the project.

"Relatives and descendants of those lost in the U-31 may now take some comfort in knowing the final resting place of the crew." The wreck will remain on the seabed and the director of the wind farm project says it will be left undisturbed.

(Another German U-boat rests off North Carolina.)

This article originally appeared on Newser: Century Later, Fate of Lost German U-Boat Revealed

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