The 4th Engineer Amphibian Brigade arrived at Oro Bay on 18 May 1944, where its headquarters opened on 23 May. Most of the rest of the brigade arrived in the area over the next few weeks, and participated in amphibious training with the 31st Infantry Division. The Boat Battalion of the 534th Engineer Boat and Shore Regiment was sent to the Bulimba Boat Yards in Brisbane, where it was engaged in assembling landing craft. It participated in the assaults on Morotai in the Netherlands East Indies on 15 September 1944, and Lingayen Gulf on Luzon in the Philippines on 9 January 1945. It was inactivated in Japan on 15 April 1946.