German submarine U - 203 German submarine " U - 203 " was a German Type VIIC submarine U - boat built for the Nazi German Kriegsmarine for service during World War II . Built as ' Werk ' 632 of Friedrich Krupp Germaniawerft AG in Kiel , she was laid down on 28 March 1940 , launched on 4 January 1941 and commissioned on 18 February under " Kapitänleutnant " Rolf Mützelburg . " U - 203 " carried out eleven patrols with the first flotilla and is credited with sinking 21 ships for 94 , 270 GRT and damaging a further three for 17 , 052 GRT . She was a member of eleven wolfpack s . She was sunk by British carrier - borne aircraft and a British warship southeast of Greenland in April 1943 . Service Record . 1st , 2nd and 3rd patrols . On 24 June 1941 , nineteen days into her first patrol while " en route " from Kiel to St . Nazaire in France , " U - 203 " attacked and sank the GRT 4 , 956 GRT British merchant ship " Kinross " , which was part of Convoy OB 336 . Later that day , she attacked the 4 , 402 GRT Norwegian vessel " Soløy " , which was with Convoy HX 133 . < br > Arriving at St . Nazaire on 29 June , the crew of " U - 203 " stayed ashore for another eleven days before the boat made her second patrol . Seventeen days into it , she attacked Convoy OG 69 which was sailing to Gibraltar . On the 27th , " U - 203 " sank the 2 , 475 GRT British merchant ship " Hawkinge " . The British " Lapland " and the Swedish " Norita " , also OG - 69 merchant ships , were sunk the following day , adding a further 1 , 330 GRT and 1 , 516 GRT respectively to the U - boat ' s record . Six days into her third patrol , on 26 September , the British ships " Avoceta " , " Lapwing " and the Norwegian " Varanberg " of Convoy HG 73 were sunk , destroying another 7 , 362 GRT of shipping . 4th , 5th and 6th patrols . Sixteen days into her fourth patrol , on 3 November , " U - 203 " attacked and sank the " Empire Gemsbuck " ( 5 , 626 GRT ) and the " Everoja " ( 4 , 830 GRT ) , British merchant ships of Convoy SC - 52 . Twenty - one days into her fifth patrol on 15 January 1942 , " U - 203 " sank a small ( 632 GRT ) Portuguese ship , the " Catalina " . Two days later , the Norwegian ship " Octavian " would also be sunk . Four torpedoes were fired at the Canadian ship " North Gaspe " , which survived the attack . One torpedo detonated close to the ship , but none actually hit . " U - 203 " s sixth patrol resulted in a total loss of 14 , 232 GRT to the Allies and two additional ships damaged , including the British merchant vessels " San Delfino " and " Empire Thrush " . Damaged were the American tanker " Henry F . Sinclair , Jr . " and the Panamanian flagged tanker " Stanvac Melbourne " . 7th , 8th and 9th patrols . A seventh patrol beginning 4 June 1942 , resulted in 32 , 985 GRT of shipping destroyed . The Brazilian " Pedrinhas " and the British were sunk on 26 June . Two days later the American Liberty Ship " Sam Houston " was torpedoed and then finished off with 43 rounds from the deck gun . The British " Cape Verde " was sunk on 9 July and the Panamanian tanker " Stanvac Palembang " on 11 July bringing the tally to five victories on this successful patrol . The next 23 day sortie was unfruitful ; however , the U - boat ' s commander , Rolf Mützelburg , died during this patrol on 11 September . Taking the opportunity to go swimming in the Atlantic southwest of the Azores , he dived from the conning tower and struck the deck with his head and shoulder when the U - boat lurched suddenly in the swell . The doctor from " U - 462 " , a ' Milk Cow ' supply submarine , arrived the next day , but too late . Rolf Mützelburg was buried at sea on 12 September 1942 in position . He was replaced by " Kptlt . " Hermann Kottman , who served as captain for the remainder of " U - 203 " s career . Her ninth patrol , beginning 15 October 1942 and terminating 6 November , yielded two further ships sunk . The British merchantmen " Hopecastle " and " Corinaldo " ( 5 , 178 and 7 , 131 GRT , respectively ) were sunk on 29 October and 30 October while traveling with Convoy SL - 125 . Loss . " U - 203 " undertook two more patrols , both unsuccessful . On 25 April 1943 while south of Cape Farewell , Greenland she was sunk by depth charges in position . She had been attacked by Fairey Swordfish aircraft operating from the British escort carrier and the British destroyer . Ten men were killed , there were 38 survivors . Summary of raiding history . " U - 203 " sank 21 ships and damaged three others for a total of 111 , 322 GRT .