One of the most successful U-boats to operate in Arctic waters,[3] she operated from Norway during 1942–1943, and then from France in 1944–1945, sailing on 15 combat patrols, sinking ten merchant ships totalling 47,640 GRT and damaging another of 7,191 GRT enough for it to be written off as a total loss.[2] She also sank the 1,200-tons Edsall-class destroyer escort USS Leopold.[4] At the end of the war U-255 surrendered to the British, and was sunk during Operation Deadlight on 13 December 1945.[1]