German submarine U - 550 German submarine " U - 550 " was a Type IXC / 40 U - boat of the " Kriegsmarine " ( the Navy of Nazi Germany ) built for service during World War II . She was laid down on 2 October 1942 by Deutsche Werft in Hamburg as ' werk ' 371 , launched on 12 May 1943 and commissioned on 28 July under the command of " Kapitänleutnant " ( Captain Lieutenant , or Lieutenant Commander ) Klaus Hänert . After training with the 4th U - boat Flotilla , she was assigned to the 10th U - boat Flotilla on 1 February 1944 in Lorient in occupied France . Patrol . She sailed from Kiel on 6 February 1944 , heading for the North Atlantic , via the gap between Iceland and the Faroe Islands and conducted weather reporting duties before sailing for Newfoundland and subsequently the northeast coast of the United States . On 22 February the boat was unsuccessfully attacked south of Iceland by a Canso flying boat of No . 162 Squadron RCAF . However , two members of the U - boat ' s crew were killed . Loss . On 16 April , south of Nantucket Island , she located convoy CU 21 , bound for Great Britain from New York City . The , one of the largest tankers in the world , was unwisely straggling behind the convoy ; " U - 550 " torpedoed her . The ship quickly caught fire and began to sink . As the vessel settled , the submerged U - boat maneuvered underneath her hull in an effort to hide from the inevitable counterattack by the convoy ' s escorts . Convoy CU - 21 was escorted by Escort Division 22 , consisting of Coast Guard - manned destroyer escort s reinforced by one Navy DE , the , which took the place of the , which had been lost in action the previous month . The escort division ' s flagship , and the rescued the tanker ' s surviving crew , while the " Joyce " detected the U - boat on sonar as the Germans attempted to escape after hiding beneath the sinking tanker . " U - 550 " s engineering officer later said , " We waited for your ship to leave ; soon we could hear nothing so we thought the escort vessels had gone ; but as soon as we started to move – bang ! " The " Joyce " delivered a depth - charge pattern that bracketed the submerged submarine . The depth charges were so well placed , a German reported , that one actually bounced off the U - boat ' s deck before it exploded . The attack severely damaged " U - 550 " and forced her to the surface , where the German sailors manned and fired their deck guns . The " Joyce " , " Peterson " and " Gandy " returned fire . " Gandy " rammed " U - 550 " abaft the conning tower and the " Peterson " dropped two depth charges which exploded near the U - boat ' s hull . Realizing they were defeated , the U - boat ' s crew prepared scuttling charges and began abandoning their boat . " Joyce " rescued 13 of " U - 550 " s crew , one of whom later died from wounds received during the fire - fight . The remainder of the U - boatmen went down with their submarine . " Joyce " delivered the prisoners of war and the " Pan Pennsylvania " survivors to the authorities in Great Britain . Attempted escape . There is a grisly postscript to the sinking of " U - 550 " . According to the Eastern Sea Frontier ' s War Diary account of the sinking , some of the crew apparently survived the sinking and were trapped in a forward compartment . They tried to leave the U - boat as it lay on the ocean floor using their escape apparatus . At 1515 on 5 May 1944 , the Coastal Picket Patrol " CGR - 3082 " recovered a body from the sea at 39° 51 ′ NN . 71° 58 ′ W . , about 93 miles ( 150 km ) ESE of Ambrose . The body was clothed in a German - type life jacket . From the markings on his clothing it was possible that the man ' s name was " Hube " . A German escape lung was found near his body as well . An autopsy performed on the body indicated that the individual died only five days before his remains were discovered – " U - 550 " had been sunk on 16 April , the corpse was found 19 days later . Two other bodies were subsequently found . The first , picked up by another picket boat , " CGR - 1989 " , at 1730 on 11 May , was fully clothed , had an escape lung and life jacket on . He was found in a rubber raft . Identification marks indicated the man was a German sailor named Wilhelm Flade , aged about 17 . The body was transferred from " CGR - 1989 " to " CGR - 1338 " on the morning of 12 May 1944 and was brought to Tompkinsville on Staten Island . On 16 May a third body was sighted and picked up by USS " SC - 630 " . It was stated that the uniform and insignia indicated the victim had been a German crewman , although he carried no identification ; he had been in the water more than 18 days . The War Diary report continued : Discovery . The wreck of U - 550 was discovered on 23 July 2012 . It lay off the coast of Massachusetts about 70 miles south of Nantucket . A team of seven divers , lead by New Jersey attorney Joe Mazraani , located the wreck using side - scan sonar after a multi - year search . The team members were Joe Mazraani , Garry Kozak , Tom Packer , Steve Gatto , Eric Takakjian , Anthony Tedeschi and Brad Sheard . Mazraani said the next step is to contact any sailors or their families from the escort vessels , the tanker and the German U - boat to share the news and show the pictures . Another trip to the site is coming , he said , adding the investigation has just started . References . Notes Bibliography