Herbert Wohlfarth Heinrich Wilhelm Herbert Wohlfarth ( 5 June 1915 – 13 August 1982 ) was a successful World War II U - boat commander . He was also a recipient of the Knight ' s Cross of the Iron Cross ( ) . The Knight ' s Cross of the Iron Cross was awarded to recognise extreme battlefield bravery or successful military leadership . Naval career . Herbert Wohlfarth began his naval career in April 1933 . After the usual training he spent more than a year on the cruiser . In May 1937 he joined the U - boat force , and like many of the later successful commanders received a solid pre - war training under Karl Dönitz . After some months as aide - de - camp in the 3rd U - boat Flotilla , in September 1938 he became watch officer on . On 19 October 1939 " Oberleutnant zur See " Wohlfarth took command of . On his first three patrols he sank nine mostly smaller ships in Scottish and Norwegian waters . The fourth patrol with " U - 14 " was for him , as for most other commanders during Operation Hartmut , supporting the invasion of Norway , without success . On 15 June 1940 Wohlfarth commissioned , also a Type IIB boat , referred to as " Einbaum " ( dugout canoe ) . But these small boats were also very successful and other well - known commanders including Hardegen , Kretschmer and Lüth won their first successes in them . Wohlfarth led " U - 137 " on three patrols during the autumn of 1940 . He sank six ships for a total of , mostly in the area south of the Hebrides . Especially notable was his torpedo hit on the 10 , 552 - ton armed merchant cruiser , damaging the ship so badly that she had to spend six months in the shipyard for repairs . On 15 December 1940 " Kapitänleutnant " Wohlfarth left " U - 137 " and two months later commissioned the Type VIIC boat . On his first patrol in the Atlantic with this new boat he sank six ships for a total of and damaged another of . On 15 May 1941 he received the Knight ' s Cross while still on patrol . On 26 May , during the return voyage , and ten days before his 26th birthday , Wohlfahrt responded to a call for all " U - boats " in the Bay of Biscay to support the ' s increasingly deteriorating position . The aircraft carrier , battlecruiser and battleship had a lucky escape during the night , unaware they had come within firing range of Wohlfarth ' s " U - 556 " , which had already fired off all its torpedoes . This was particularly galling for Wohlfahrt , as " U - 556 " and " Bismarck " had exercised together in the Baltic . " U - 556 " continued to shadow the British forces , reporting their position and guiding other U - boats to the area . Wohlfarth witnessed the night battles between " Bismarck " and British destroyers . Prisoner of war . On 19 June 1941 Wohlfarth started his second patrol on " U - 556 " , but just eight days later his boat was sunk in the North Atlantic southwest of Iceland by the British corvette s , and . He and most of his crew were captured ; one officer and four men were killed . Wohlfarth then spent more than six years in English and Canadian prisoner of war camps . His war record stood at 21 ships sunk , totalling , and three more damaged , totalling . He returned to Germany on 14 July 1947 . Wohlfarth died on 13 August 1982 in Villingen , Germany , at the age of 67 years old . On 8 June 1989 , three days after what would have been his 74th birthday , the wreck of " Bismarck " was located .