German submarine U - 977 German submarine " U - 977 " was a World War II German Type VIIC U - boat which escaped to Argentina after Germany ' s surrender . The submarine ' s voyage to Argentina led to many legends and apocryphal stories : that it had transported Adolf Hitler or Nazi gold to South America , that it had made a 66 - day passage without surfacing or that it had made a secret voyage to Antarctica . Voyage to Argentina . " U - 977 " was launched in 1943 . She was used in training and made no war patrols during her first two years of service . On 2 May 1945 she was sent on her first war patrol , sailing from Kristiansand , Norway , under the command of Oberleutnant Heinz Schäffer ( 1921 – 1979 ) . Schäffer ' s orders were to enter the British port of Southampton and sink any shipping he found there . This would have been a very dangerous assignment for a Type VII boat . When Admiral Dönitz ordered all attack submarines to stand down on 5 May 1945 , " U - 977 " was outbound north of Scotland . Oberleutnant Schäffer decided to sail to Argentina instead . During later interrogation , Schäffer said that his main reason for this was German propaganda broadcast by Goebbels , which claimed that the Allies ' Morgenthau Plan would turn Germany into a " goat pasture ” and that all German men were to be " enslaved and sterilized " . Other factors were the poor conditions and long delay in being repatriated suffered by German POWs at the end of World War I ( see Forced labor of Germans after World War II ) , and the hope of better living conditions in Argentina , which had a large German community . Schäffer offered the married crewmen the choice to go ashore in Europe . 16 men opted to so , and were landed from dinghies on Holsenöy Island near Bergen on 10 May . " U - 977 " then sailed to Argentina . Schäffers version of the voyage states that from 10 May to 14 July 1945 inclusive she made a continuous submerged Schnorchel passage , " at 66 days the second longest in the war ( after ' s 68 days ) " . A conflicting account from the U . S . Navy ( USN ) report of 19 September 1945 contradicts Schäffers version . The USN Report on the " U - 977 " crew interrogations was compiled within a month of the boat ' s surrender ; it makes no mention of any 66 - day voyage always submerged , an interesting omission since the details of the voyage must have been still fresh in the minds of the German crew . They told the American interrogators that " U - 977 " " made for the Iceland Passage on course 300º ( that is , a little North by West ) diving once on sighting a plane and once on sighting a ship ( this means she was surfaced at the time ) : " she was also D / F ' d many times late in May " . According to the USN report the submarine stopped in the Cape Verde Islands for a short break en route , then completed the trip traveling on the surface using one engine . Crossing the equator on 23 July , she arrived in Mar del Plata , Argentina on 17 August after 99 days at sea from Bergen and a voyage of . In general , historians have tended to discount the USN report and accepted Schäffer ' s report as the more accurate version . The Schäffer map provides only three dates : 8 May " End of the war " , 24 July 1945 " crossed Equator " , and 17 August 1945 " arrived at Mar del Plata " . Schäffer maintained that he crossed the Equator on 23 or 24 July 1945 , on this date both the US Navy and Schäffer agree . Comparing the USN report with Schäffer ' s account , the impression is of two separate voyages from Norway meeting up at the Equator on 23 July 1945 . After arriving at Mar del Plata on 17 August 1945 , " U - 977 " was surrendered to the Argentine Navy . She was later towed to Boston and given to the U . S . Navy on 13 November 1945 . On 13 November 1946 , she was sunk off Cape Cod by USS " Atule " during torpedo trials . The crew was transferred into U . S . jurisdiction by presidential decree on 22 August 1945 and flown out for interrogation in the United States . Schäffer later wrote a book : " U - 977 – 66 Tage unter Wasser " ( " U - 977 – 66 Days Under Water " ) , the first postwar memoir by a former U - boat officer . It was published in 1952 , and was translated into English under the title " U - boat 977 " . In the arts . Documentary film U - 977 - 66 DAYS UNDER WATER directed by Nadine Poulain , Schäffer ' s granddaughter , currently in the final stages of production .