German submarine U - 209 German submarine " U - 209 " was a Type VIIC U - boat of the " Kriegsmarine " during World War II . The submarine was laid down on 28 November 1940 by the Friedrich Krupp Germaniawerft yard at Kiel as ' werk ' 638 , launched on 28 August 1941 and commissioned on 11 November under the command of " Kapitänleutnant " Heinrich Brodda . She was lost in May 1943 , possibly due to a diving accident . Operational career . " U - 209 " began her service career as part of the 6th U - boat Flotilla for training , she then commenced operations with the same organization on 1 March 1942 . She was re - assigned to the 11th flotilla on 1 July 1942 . She was with the 1st flotilla until her loss on 7 May 1943 . She carried out a total of seven patrols and was a member of nine wolfpack s . 1st patrol . She made the short journey from Kiel to the German island of Helgoland and then departed on her first patrol on 15 March 1942 . She headed north , into the Norwegian Sea , then east . The boat was attacked by the armed trawler HMS " Blackfly " on the 28th ; but conditions were so bad that the ship could not use her armament because it was frozen . Depth charge s were little better , at least one malfunctioned . The submarine also came under attack from two minesweepers , HMS " Hussar " and " Gossamer " in the Barents Sea on the 29th . " U - 209 " escaped . 2nd patrol . The boat ' s second sortie began in the Norwegian port of Kirkenes in the far north of the country . She patrolled the vicinity of Bear Island , then sailed south and southwest , before docking in Bergen , also in Norway . 3rd and 4th patrols . Her third and fourth patrols , in June and July 1942 , covered the Norwegian Sea and the passage between Bear Island and Svalbard , it saw her depart Bergen and return to Kirkenes . 5th patrol . The boat attacked a small Soviet convoy on 17 August 1942 , near Mateev Island in the eastern Barents Sea . She sank the " Komiles " , the " Komsolec " , " SH - 500 " and " P - 4 " , ( two tugs and two barges ) , with her gun . 6th and 7th patrols and loss . Patrol number six , at 35 days , was her longest . It took her northwest of Bear Island . By now the boat had returned to Kiel , from where she departed for the last time on 6 April 1943 . She was attacked by a British B - 17 Flying Fortress of No . 220 Squadron RAF southeast of Iceland , on the 16th , sustaining damage to her periscope . She was also attacked by a Canadian PBY Catalina ( known as a Canso ) of No . 5 Squadron RCAF on 4 May . The damage incurred included her radio transmitter , so a message to " Bdu " ( U - boat headquarters ) , was sent via " U - 954 " . " U - 209 " was recalled , but she was never heard from again ; her loss might be explained by a diving accident . Whatever the reason , forty - six men died ; there were no survivors . Afterword . " U - 209 " was originally thought to have been sunk by the frigate HMS " Jed " and the sloop HMS " Sennen " on 19 May 1943 . This attack was responsible for the demise of " U - 954 " . U - 209 was nicknamed Brno by the southmoravian town in where the crew took holiday in February 1943 . They were invited by SS - Sturmbannführer Konrad Nussbaum , chief of Brno Kripo whose son was one of the crew . Brno municipality got as a gift the model of submarine ( the photo exist ) but model itself probably lost after the end of WWII .