Inferno: The World at War, 1939-1945

by Max Hastings

In May 1943 47 U-boats were sunk, and almost a hundred in the year as a whole. Sinkings of German submarines by aircraft alone rose from 5 between October 1941 and March 1942, to 15 between April and September 1942, to 38 between October 1942 and March 1943. Dönitz found himself losing a U-boat a day, 20 percent of his submarine strength gone in a month. He was obliged to drastically curtail operations. There was a steep fall in merchant ship sinkings, so that by the last quarter of 1943 only 6 percent of British imports were lost to enemy action. The wartime Atlantic passage was seldom less than a gruelling experience, but for the rest of the war British and American forces dominated the ocean, challenged by a shrinking U-boat force with crews whose inexperience and waning morale were often manifest.