Convoy HI-72: US Submarines versus Japanese Escorts in the Pacific War

Abstract

The Japanese convoy HI-72, attacked by a wolf pack of American submarines after it departed Singapore in September 1944, has gained some notoriety because two of the ships sunk carried Allied prisoners of war. Beyond this, however, the convoy’s fate highlights some of the factors which made US submarines so effective while disclosing the shortcomings of Japanese escorts. An examination of the extant battle reports by the convoy ships reveals that the Japanese were aware of many of the factors which contributed to their shipping losses, but also unaware of how heavily the odds were stacked against them at this stage of the war.