Kestrel II, a 93-ton motor boat, was built in 1912 at Greenport, on New York's Long Island, as a pleasure craft. Leased by the Navy during the first months of U.S. participation in World War I, she was placed in commission as USS Kestrel II (SP-529) in early June 1917. During the next year and a half, she operated on patrol duties in Long Island Sound, based at New London, Connecticut. Kestrel II decommissioned and was returned to her owner in January 1919.