German submarine U - 106 ( 1940 ) German submarine " U - 106 " was a Type IXB U - boat of the Nazi German " Kriegsmarine " that operated during World War II . She was laid down on 26 November 1939 at AG Weser in Bremen as ' werk ' 969 , launched on 17 June 1940 and commissioned on 24 September . She was armed with six torpedo tubes and a 10 . 5 cm SK C / 32 naval gun . " U - 106 " was assigned to the 2nd U - boat Flotilla on 24 September 1940 , in which she would serve for nearly three years . " U - 106 " was one of the most successful German submarines of World War II . She completed 10 wartime patrols and sank 22 ships totalling . She also damaged two ships totalling 12 , 634 GRT , one auxiliary warship of 8 , 246 GRT and the battleship . " U - 106 " helped to catalyze Mexico ' s entry into World War II on the side of the Allies by sinking one of two oil tankers ; the " Faja de Oro " . ( The other was the " Potrero del Llano " , sunk by " U - 564 " ) . Service history . 1st patrol . " U - 106 " departed Kiel for her first patrol on 4 January 1941 which was to be conducted in the Atlantic Ocean . Her route included negotiating the ' gap ' between the Faroe and Shetland Islands . She sailed north - west of Rockall and sank two ships : the " Zealandic " on the 17th and the " Sesostris " on the 29th . There were no survivors from either vessel . The boat docked in Lorient in occupied France on 10 February . 2nd patrol . For her second patrol , " U - 106 " departed Lorient on 26 February 1941 . She would not return to France until 17 June , 112 days later . The boat headed for the coast of west Africa . Her first victim on this patrol was the " Memnon " , which went to the bottom west of Cape Blanco , French West Africa on 11 March . She sank seven more ships and damaged two others , including the battleship HMS " Malaya " in the vicinty of Senegal and the Cape Verde Islands . One of the seven , the " Eastlea " , had her back broken and sank within ten minutes . 3rd patrol . Sortie number three and the U - boat failed to find any targets . She had left Lorient on 11 August 1941 and returned there a month later ( on 11 September ) , having covered the ocean west of Ireland , also west of the Azores and from north of that island chain to the Portuguese mainland . 4th patrol . Any success on the boat ' s fourth sally was marred on 23 October 1941 by the discovery that an entire watch , ( four men ) , had been washed overboard in heavy seas on the western edge of the Bay of Biscay . " U - 106 " sank one ship , the " King Malcolm " on the 28th and damaged one other , the USS " Salinas " , on the 30th . She was then hunted for nine hours and seriously damaged by the escort vessels of convoy ON - 28 . 5th patrol . For her fifth patrol , " U - 106 " sailed along the eastern coast of the United States and sank five ships , during the so - called " Second Happy Time " . Amongst them were the and the tanker , the latter ship being dispatched with her 10 . 5 cm deck gun . She had left Lorient on 3 January 1942 and returned on 22 February . 6th patrol . Patrol number six also benefitted from a change of operational area to the Gulf of Mexico , where the boat sank five more ships and damaged a sixth . One of them , the tanker " Faja de Oro " , on 21 May 1942 , was the second ship to be sunk which helped to facilitate Mexico ' s declaration of war on Germany on 1 June . 7th and 8th patrols . " U - 106 " was attacked by a Vickers Wellington of No . 311 Squadron RAF in the Bay of Biscay on 27 July 1942 . The first watch officer ( 1WO ) was killed ; the commander was wounded , forcing the boat to put about , returning to Lorient on the 29th , just five days after setting out . . The submarine crossed the Atlantic once more , sinking the " Waterton " in the Gulf of St . Lawrence on 11 October 1942 . 9th patrol . This foray was comparatively uneventful , starting on 17 February 1943 and finishing on 4 April . No ships were attacked . 10th patrol and loss . The U - boat ' s 10th and final patrol began on 28 July 1943 ; she was sunk on 2 August of that year off northern Spain , after being damaged by a Wellington of No . 407 Squadron RCAF . " U - 106 " tried to join E - boat s ( German surface torpedo boats ) , but was spotted by a Sunderland flying boat of 228 Squadron flown by Flying Officer Reader Hanbury . Although the anti - aircraft guns on " U - 106 " fended off the British machine , " U - 106 " was finished off by another Sunderland of No . 461 Squadron RAAF flown by Flight Lieutenant A . F . Clarke . According to the Allied crews and photographs taken of the attack , the U - Boat partially exploded , before sinking vertically . 22 of " U - 106 " s 48 - man crew were killed . 26 survived the attack and were later picked up by German E - boats .