675 men. sinks Inverilen and Jeremiah Van Rensselaer from convoy HX 224. February 7, 1943 U-boats sink nine ships from convoy SC 118. February 15, 1943 A new system of fast CU convoys is initiated to speed the flow of petroleum products from Caribbean Sea refineries to Liverpool. March March 7, 1943 U-boats sink seven ships for convoy SC 121. March 10, 1943 U-boats sink four ships from convoy HX 228. March 16, 1943 The largest convoy battle of World War II begins around convoys HX 229 and SC 122. March 28, 1943 U-boats sink four ships from convoy SL 126. April April 4, 1943 U-boats sink three ships from convoy HX 231. April 12, 1943 sinks three ships from convoy HX 232. April 17, 1943 U-boats sink Fort Rampart from convoy HX 233. April 22, 1943 sinks Amerika from convoy HX 234. May May 6, 1943 The battle for convoy ONS 5 reaches a climax with the destruction of seven U-boats. May 7, 1943 sinks Laconikos from convoy SL 128MK. May 11, 1943 sinks Antigone and Grado from convoy SC 129. July July 31, 1943 In a coordinated action, one American and two Brazilian maritime patrol aircraft sink the then modern U-199. September September 8, 1943 Italy surrenders, and Britain starts to redeploy their Mediterranean destroyers to the Atlantic. October October 9, 1943 sinks Yorkmar from convoy SC 143. October 31, 1943 sinks Hallfried from convoy SL 138MK. December December 26, 1943 Ships of the Royal Navy sink the German battleship off Norway's North Cape. 1944 April April 6, 1944 sinks Ruth I and South America from convoy SC 156. July July 20, 1944 sinks the freighter-troopship Vital de Oliveira, the only Brazilian military ship sunk due to submarine action at WWII, and the last Brazilian vessel to be torpedoed in that war. August August 3, 1944 The largest convoy of World War II, convoy HX 300, arrives in the British Isles without loss. September September 8, 1944 sinks Empire Heritage and Pinto from convoy HX 305. 1945 January January 27, 1945 sinks Solor from convoy HX 332. March March 2, 1945 sinks Novasli and King Edgar from convoy SC 167. April April 18, 1945 sinks Empire Gold and Cyrus H McCormick from convoy HX 348. Month-by-month summaries 1939 September Allied shipping losses total 53 vessels. 41 vessels totaling 153,800 tons are lost to submarines. German losses are two