German submarine U - 309 German submarine " U - 309 " was a Type VIIC U - boat of the Nazi German " Kriegsmarine " during World War II . The submarine was laid down on 24 January 1942 at the Flender Werke yard at Lübeck , launched on 5 December 1942 , and commissioned on 27 January 1943 under the command of " Oberleutnant zur See " Hans - Gert Mahrholz . She sailed on nine combat patrols , but damaged only one ship , before being sunk off Scotland on 16 February 1945 . Service history . 1st patrol . After training with the " 8th U - boat Flotilla " at Königsberg , " U - 309 " was transferred to the " 11th U - boat Flotilla " based in Bergen on 1 August 1943 , Norway , for front - line service . The U - boat departed Kiel on 26 August , arriving at Bergen seven days later , on 1 September . From there she sailed out into the Norwegian Sea on 13 September , and arrived in Trondheim six days later on the 18th . As " U - 309 " was then reassigned to the " 9th U - boat Flotilla " based at Brest in France . She left Trondheim on 25 September , and sailed out into the mid - Atlantic to patrol , before arriving at Brest on 7 November . During this patrol , on 30 September , " U - 309 " suffered her only casualty , when " Mechanikergefreiter " Erich Jungmann was lost overboard while working out on deck . 2nd patrol . " U - 309 " s next patrol took her from Brest , on 19 December 1943 , out into the Atlantic west of Ireland , then back to Bordeaux on 14 February 1944 . In April 1944 the U - boat was fitted with a " Schnorchel " underwater - breathing apparatus . 3rd - 5th patrols . In June and July 1944 " U - 309 " made two short patrols in the Bay of Biscay , before finally achieving success during her fifth patrol . The U - boat sailed from Brest on 12 July 1944 and into the English Channel . There , at 21 : 00 on 24 July , she fired three LuT pattern - running torpedoes at Convoy FTM - 47 , en route from Juno Beach in Normandy to Southend , and hit the 7 , 219 ton British Liberty ship " Samneva " . Badly damaged , the ship was beached at Southampton , but then broke in two and was declared a total loss . " U - 309 " returned to Brest on 3 August . 6th and 7th patrols . As the French bases fell to the advancing Allies , " U - 309 " was transferred again , this time to the " 33rd U - boat Flotilla " based at Flensburg . Under her new commander " Oberleutnant zur See " Herbert Loeder she left La Pallice on 29 August 1944 , and sailed around the British Isles to Stavanger , Norway , arriving on 13 October . The U - boat left there after only two days , sailing to Flensburg by the 21st . 8th and 9th patrols . " U - 309 " left Germany on 30 January 1945 , sailing to Horten in Norway , arriving there on 2 February . She departed on 8 February , and headed into the waters east of Scotland . Loss . There , on 16 February 1945 , " U - 309 " was shadowing Convoy WN - 74 into the Moray Firth when she was detected by the Canadian River class frigate with ASDIC ( sonar ) . The first attack on the U - boat produced some oil on the surface . Two further attacks were carried out using the Hedgehog anti - submarine mortar , which produced more oil . The fourth attack using depth charge s produced wreckage including charts , signal books and cork insulation material . " U - 309 " sank in position . All 47 aboard were lost . Discovery . The wreck of what is believed to be " U - 309 " was located on 17 May 2001 , 25 miles off Wick in of water . There are no identifying features , but the Type VIIC U - boat is close to the reported position of " U - 309 " s sinking , and the damage sustained is consistent with that caused by depth charges . However there is a possibility that the wreck may be the , which went missing in the North Sea in November 1944 and has never been found . However , a deck gun mount was found on the wreck , which would rule out the possibility of it being " U - 1020 " .