Nantucket (Bernd F. Laeschke – Juli 2012): Divers did locate U-550, a World War II German submarine, in deep water about 70 miles from the Nantucket Island, Massachusetts, according to several reports in German news outlets. The U-boat, built by the Deutsche Werft in Hamburg, was launched on May 12, 1943, and commissioned on July 28, 1943 under the command of Lieutenant Commander Klaus Hänert.
After training runs with the 4th U-boat Flotilla, the 252 feet (76.8 meter) Type IXC/40 oceangoing submarine was assigned to the 10th U-boat Flotilla on February 1, 1944. Several days later, U-550 left the city of Kiel, Germany, and headed into the North Atlantic. Two crew members were lost during a fight with a Consolidated PBY Catalina, an American flying boat, on February 22, 1944. However, the German submarine escaped the attack.
Armed with 22 torpedoes, the crew of U-550 located convoy CU 21 bound for Great Britain and torpedoed the SS Pan-Pennsylvania, at the time one of the largest tankers in the world, on April 16, 1944. The 11,016 gross register tons (GRT) ship was badly damaged during the attack and began to sink. USS Joyce (DE-317), the escort division's flagship, detected the U-Boat on sonar and severely damaged it with a barrage of depth charges. U-550 surfaced, and did finally sink after it was rammed by the USS Gandy (DE-764) and two additional depth charges, dropped from the USS Peterson (DE–152).
A team of seven scuba divers discovered the wreck of the German submarine on July 23, 2012, using sonar. The team searched several years for U-550, and plans to return to the site and continue exploring the wreck.