German submarine U - 37 ( 1938 ) German submarine " U - 37 " was a Type IXA U - boat of the Nazi German " Kriegsmarine " during World War II . The submarine was laid down on 15 March 1937 at the AG Weser yard in Bremen , launched on 14 May 1938 , and commissioned on 4 August 1938 under the command of " Kapitänleutnant " Heinrich Schuch as part of the 6th U - boat Flotilla . Between August 1939 and March 1941 , " U - 37 " conducted eleven combat patrols , sinking 53 merchant ships , for a total of ; and two warships , the British sloop HMS , and the French submarine " Sfax " ( Q182 ) . " U - 37 " was then withdrawn from front - line service and assigned to training units until the end of the war . On 8 May 1945 the U - boat was scuttled in Sonderburg Bay , off Flensburg . " U - 37 " was the sixth most successful U - boat in World War II . Service record . First patrol . " U - 37 " left Wilhelmshaven , with " Kapitänleutnant " Heinrich Schuch in command , on 19 August 1939 . The boat operated for nearly four weeks in the North Atlantic , returning to port on 15 September 1939 . Second patrol . " U - 37 " left Wilhelmshaven on 5 October 1939 to conduct operations in the North Atlantic now under the command of " Kapitän zur See " Werner Hartmann . During this patrol she sank eight ships : four British , two Greek , one French and one Swedish , including the British steam freighter " Yorkshire " which was traveling with the Allied convoy HG - 3 , sailing from Gibraltar to Liverpool , England . Hartmann returned his boat to port on 8 November after nearly five weeks at sea . Third patrol . On 1 January 1940 " U - 37 " was reassigned to the 2nd U - boat Flotilla based at Wilhelmshaven . On 28 January 1940 the U - boat departed for the North Atlantic , with Werner Hartmann in command . As on his previous patrol , Hartmann sank eight ships , this time three British , two Norwegian , one Danish , one French and one Greek . Of these ships , two were in convoy at the time . " U - 37 " returned to Wilhelmshaven on 27 February . Fourth patrol . " U - 37 " departed Wilhelmshaven on 30 March for Werner Hartmann ' s third consecutive patrol , this time around Norway . Again , Hartmann proved successful , sinking three ships ; the Norwegian " Tosca " , the Swedish " Sveaborg " and the British " Stancliffe " . After patrolling for over two weeks , the U - boat returned to Wilhelmshaven on 18 April . Fifth patrol . Under a new captain , " Kapitänleutnant " Victor Oehrn , " U - 37 " departed from Wilhelmshaven on 15 May for a patrol around Portugal and Spain . " U - 37 " had her most successful mission , hitting eleven ships , sinking ten of them . Three French ships were sunk , two Greek , two British , one Swedish , one Argentinian , one Finnish ; one British ship was damaged . After three and a half weeks at sea , " U - 37 " returned to Wilhelmshaven on 9 June . The neutral Argentinian ship was the " Uruguay " , sailing from Rosario to Limerick with a cargo of maize . " U - 37 " surfaced and stopped the " Uruguay " and examined her papers , then sank her with scuttling charges . Her crew of 28 were left in their lifeboats . Fifteen died , 13 survived . Sixth patrol . " U - 37 " sailed from Wilhelmshaven on 1 August , again with Victor Oehrn in command . This week and a half long patrol in the Atlantic off the west coast of Ireland resulted in the sinking of a single British ship , the " Upwey Grange " . " U - 37 " returned to port on 12 August , but rather than head back to Wilhelmshaven , she made for Lorient in France , where the " 2nd U - boat Flotilla " was now based . Seventh patrol . For the first time , " U - 37 " began a patrol from a location other than Germany , in Lorient on 17 August , with Victor Oehrn in command once more . It was to focus on operations off the south - west coast of Ireland . Seven ships were sunk during this voyage ; five of which were British , one Norwegian , and one Greek . Of these ships , one was from the convoy OA - 220 , the British " Brookwood " , traveling from Britain to the United States , two were from the convoy SC - 1 , the British sloop HMS " Penzance " and " Blarimore " , sailing from Sydney , Australia , to the United Kingdom . After two weeks at sea , " U - 37 " returned to Lorient on 30 August . Eighth patrol . On 24 September , " U - 37 " departed Lorient on Victor Oehrn ' s fourth patrol , in which he would sail to the North Atlantic . During this month long operation " U - 37 " sank six ships , four of which were in convoy at the time of attack , all of which were British . Five of these six ships were sailing under the British flag , while the sixth was from Egypt . The British ship " Corrientes " was sunk as part of convoy OB - 217 , sailing from Liverpool to North America . The " Heminge " was sailing as part of convoy OB - 220 , also sailing from Liverpool to North America . The " British General " was sunk while sailing as part of convoy OA - 222 , sailing from Britain to North America . The fourth ship sunk was the British " Stangrant " , sailing as part of the convoy HX - 77 from Halifax to the United Kingdom . The U - boat returned to Lorient on 22 October . Ninth patrol . After over a month in port , " U - 37 " departed with a new captain , " Oberleutnant zur See " Asmus Nicolai Clausen on 28 November for operations around north - west Africa and Spain . Seven ships were sunk during this patrol ; two French , two Swedish , two British and one Spanish . Of these seven ships , three were in convoy at the time of their sinking . The Swedish " Gwalia " and " Daphne " and the British " Jeanne M " were sailing as part of convoy OG - 46 from Britain to Gibraltar . The French vessels , the oiler " Rhône " and the submarine " Sfax " belonged to Vichy France and were sunk in error . After five weeks on the high seas , " U - 37 " returned to Lorient on 14 January 1941 . Tenth and eleventh patrols . " U - 37 " left Lorient on 30 January 1941 to patrol off the coast of Portugal . On 8 February she spotted Convoy HG - 53 . The next day , " U - 37 " sank two British ships , " Courland " and " Estrellano " . The third merchant vessel that " U - 37 " sank on her tenth patrol was the British ship " Brandenburg " , on 10 February . The U - boat then returned to Lorient on 18 February after spending 20 days at sea and sinking 4 , 781 tons of shipping . Leaving Lorient for the final time on 27 February 1941 , " U - 37 " s last patrol took her to the waters south of Iceland . There she sank two vessels , the Greek cargo ship " Mentor " on 7 March , and the Icelandic trawler " Pétursey " on the 12th . After spending 24 days at sea , " U - 37 " entered the port of Kiel on 22 March . Training boat . On 1 May 1941 " U - 37 " was reassigned to the 26th U - boat Flotilla , based at Pillau , as a training U - boat . She was transferred to the 22nd U - boat Flotilla , based at Gotenhafen on 1 April 1942 , and finally to the 4th U - boat Flotilla on 1 July 1944 , where she remained until the end of the war . She was scuttled by her crew in May 1945 .