In late 1941, "Portmar" was chartered by the United States Department of War to carry supplies to the Philippines but due to the Japanese invasion of the Philippines was retained in Australia. She was used in February 1942 to carry reinforcements from Darwin for the defenders of Timor prior to the Japanese invasion. The reinforcement convoy was shadowed by Japanese planes and attacked, forcing its cancellation. "Portmar" returned to Darwin on 18 February, and was still in harbour the next day when Japanese carrier-based aircraft attacked the city in the first ever attack on Australia. The ship was heavily damaged, and run aground to prevent sinking.