Battle of the Bismarck Sea, 1943
In February, 1943, the Japanese had just successfully evacuated 10,600 men from Guadalcanal, but the remainder of their holdings were going to need major reinforcement to hold off the Allied advance. A convoy was planned for early March, running from Rabaul in the Solomons to Lae in New Guinea. Consisting of eight troop transports, and eight destroyers, the convoy sailed on 28 February. The Japanese were well aware that the run would be dangerous, due to the strength of Allied air power in the region, but it was still necessary, and the risk was judged worth it. Allied intelligence had figured out the convoy's schedule, and it was located on 2 March. In what became known as the Battle of the Bismarck Sea, the convoy was subjected to three days of heavy air attack. PT-boats joined in on the 3rd-5th, making torpedo attacks and finishing off the crippled transport Oigawa Maru. By the end of it, all eight transports had been sunk, along with four of the escorting destroyers. The Japanese lost twenty aircraft, with at least 2,890 dead. Allied losses were just thirteen killed, and six aircraft lost. Allied intelligence also scored a major coup when a complete roster of Japanese Army officer postings was captured from survivors, allowing them a much more complete picture of the IJA deployments. Of the 6,900 troops bound for Lae, 1,200 actually made it. This would be the last reinforcement of New Guinea by ship, effectively dooming the Japanese position on the island.