The Nantucket was used as a floating lighthouse built in 1950. From 1950 to 1969 it served as "The San Francisco" and was stationed 3 miles off the Golden Gate Bridge. From 1969 to 1971 it served as "Blunts Reef" off Cape Mendicino, California. The ship came to the East Coast in 1971 and served as the "Portland" off Portland, Maine until 1975. The Nantucket then was stationed 45 miles southeast of Nantucket Island and was decommissioned in 1985.