Former names retained.
Mystery (SP‑16), a fast, twin‑engined motorboat, was surveyed early in 1917 for use in the 3d Naval District. However, she was not taken over by the Navy.
(Motorboat: t. 26 (gr.); l. 71'; b. 13'; dr. 3'6"; s. 24 k.; cpl. 10; a. 1 3‑pdr., 1 1‑pdr., 2 mg.)
Mystery (SP‑428), a wooden‑hulled motorboat powered by two 400‑horsepower Duesenherg engines, was built by Luders Marine Construction Co., Stamford, Conn., in 1917; acquired by the Navy under free lease from her owner, Mr. Ralph Pulitzer of New York City, 18 June 1917; enrolled in the Naval Coast Defense Reserve and delivered 24 July 1917; and commissioned 25 July 1917, Lt. (jg.) Ralph Pulitzer in command.
Assigned to the 2d Naval District, Mystery operated out of the section base at Block Island, R.I., during World War I. She patrolled the coastal waters of Connecticut and Rhode Island as well as approaches to Long Island Sound. She was returned to her owner 11 January 1919.