USS PC-815 was a PC-461-class submarine chaser built for the United States Navy during World War II. It was commanded for about eighty days in 1943 by L. Ron Hubbard, who later became the founder of Scientology. After Hubbard was removed from command for inadvertently shelling Mexican territory, the PC-815 served as a shore patrol vessel off San Diego, California. She was lost with one of her crew in September 1945 after being hit by the destroyer USS Laffey.