USS Porpoise (SP-4)

USS Porpoise (SP-4) was probably a motorboat or yacht which the United States Navy at least considered for service – and may have placed in service – during World War I as a patrol vessel.

Porpoise received one of the earliest section patrol numbers, indicating that she was a privately owned motorboat or yacht which the U.S. Navy during 1916 or early 1917 at least considered for World War I service as a patrol vessel. No records have been found describing Porpoise's construction, acquisition, naval service (if any), or physical characteristics and performance; her records may have been lost or destroyed. She may have seen active naval service, although some boats which received section patrol numbers were never commissioned or, in some cases, never even acquired by the Navy, so it also is possible that the lack of records reflects a lack of naval service for Porpoise.