The swastikas gave it away. Eighty years after a British submarine sank the German warship Karlsruhe during World War II, images from a remotely operated vehicle have helped identify the wreckage. The cruiser is sitting upright 1,607 feet below the surface off the southern coast of Norway, Live Science reports. "Karlsruhe is an impressive sight," an archaeologist at the Norwegian Maritime Museum said. "Most big warships in deep waters have turned [over] on the way down to the seabed because of their large superstructure, but the Karlsruhe has gone straight down and is resting on its keel." The ship's distinctive gun turrets helped with the identification, as did the Nazi symbols. The Karlsruhe is the only large German warship sunk during the invasion of Norway whose location was unknown, the archaeologist said.
Engineers for Statnett, which operates Norway's electric grid, found the wreck during a sonar survey in 2017, per Smithsonian Magazine. The remote vehicle wasn't sent down till this summer. The 571-foot cruiser was hit on April 9, 1940, by torpedoes from the British sub, opening huge holes in the hull, as it left the port of Kristiansand after aiding in the German attack. The crew was ordered to abandon ship, and a German torpedo boat deliberately finished off the Karlsruhe. "The ship was an important actor at a crucial time of Norwegian modern history," the archaeologist said. It had nine 15-centimeter guns and could do 32 knots—37 mph. "Apart from the bow, which blew up when the last German torpedo hit the ammunition storage," he said, "the ship is practically intact." (Read more World War II stories.)