Tuna, a 98-foot motor boat, was built in 1911 at Baltimore, Maryland, for use as a pleasure craft. She was leased by the Navy, commissioned as USS Tuna (SP-664) in June 1917, and employed on patrol duties in the vicinity of Long Island and Martha's Vinyard. No longer needed after the end of World War I, Tuna was returned to her owner in January 1919.