Seven Seas proceeded to the 7th Naval District on 8 May 1942, arriving at Key West, Florida, later that month. On 9 April, the auxiliary, full-rigged ship assumed duties as station ship at Key West.
Seven Seas remained at Key West until after the heyday of coastal U-boat strikes. As the dangers lessened, she was placed out of service and laid up at the Coast Guard Patrol Base, Port Everglades, Florida, on 22 May 1944. Seven Seas was struck from the Navy List on 29 July 1944.