A former name retained.
(S. P. 654: displacement 23; length 55'; beam 11'4"; draft 2'6"; speed 11 knots; armament 1 1-pounder)
Hippocampus, a gasoline-powered yacht, was built by New York Yacht, Launch, & Engine Co. in 1912 and was leased by the Navy from her owner, James F. Porter, of Chicago, Ill., 21 June 1917. She commissioned 25 June at Rockland, Maine, Chief Boatswain Mate F. L. Greene in command.
Assigned to the 1st Naval District, Hippocampus served as a harbor patrol craft at the harbor entrance, Rockland, Maine, and in Penobscot Bay during World War I. She decommissioned 30 November 1918 and was returned to her owner 5 April 1919.