"Apollo" transited the Panama Canal on 13 November; paused briefly at San Diego, California, for replenishment; and continued on to Pearl Harbor, Hawaii. On 10 December, the ship set a course for Guam, Mariana Islands, and arrived in Apra Harbor 11 days later. She then commenced providing services to various submarines of the Pacific Fleet. Her tour of duty at Guam ended on 10 July 1945, when the vessel got underway to return to Pearl Harbor. Shortly after her arrival, her crew resumed submarine tending activities.