USS Manatee (SP-51)

USS Manatee (SP-51) was a United States Navy patrol vessel in commission from 1917 to 1919. Manatee was originally a private motorboat built in 1916 by the Matthews Boat Company of Port Clinton, Ohio. The U.S. Navy acquired her from her owner, E. J. Kruce of Detroit, Michigan, on 24 April 1917 for use as a section patrol boat during World War I. She was commissioned on 25 May 1917 as USS Manatee (SP-51).

Assigned to the 9th Naval District, Manatee performed patrol duties on the Great Lakes for the duration of World War I. These duties primarily involved observing traffic and maintaining order.

Following the end of World War I, Manatee was stricken from the Navy List on 25 November 1919 and sold on 17 December 1919. Her subsequent fate is unrecorded.