Kestrel II was built in 1912 as a private motor yacht of the same name by Percy Tuttle at Greenport on Long Island, New York, for D. Herbert Hostetter of New York City. On 2 June 1917, the U.S. Navy acquired her from her owner for use as a section patrol vessel during World War I. She was commissioned as USS Kestrel II (SP-529) on 4 June 1917 at Newport, Rhode Island, with Chief Boatswain's Mate C. E. Black, USNRF, in command. Assiigned to the 2nd Naval District and based at New London, Connecticut, Kestrel II operated on patrol duties in Long Island Sound for the rest of World War I.