USS Porpoise has been the name of more than one United States navy ship, and may refer to:
USS Sea Hawk (SP-2365) was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1919.
Calf Pasture Beach is an historically significant park and beach in Norwalk, Connecticut.
The second USS Hatteras (1917) was a Cunard Line freighter acquired by the U.S. Navy during World War I and was used to transport men and war materials to France. Post-war she was returned to the U.S. Shipping Board as redundant to needs.
USS Kanawha II (SP-130)/USS Piqua (SP-130) -- was a yacht acquired by the U.S. Navy during World War I. She was placed into service as an escort for Allied convoys traveling across the dangerous North Atlantic Ocean. German U-boats were active in sinking Allied ships, and Kanawha II provided a valuable service as a lookout and in one instance attacked one and drove it off. Post-war she was returned to her pre-war owner in July 1919.
USS Halcyon II (SP-582) was a yacht acquired by the U.S. Navy during World War I. She was outfitted as an armed patrol craft and stationed in Boston harbor in Massachusetts. She spent much of the war patrolling the Massachusetts waterways for German submarines and, in 1919, was decommissioned after being damaged in a collision.
The first USS Courtney (SP-375) was a patrol boat and minesweeper in commission in the United States Navy from 1917–1919.
USS Helena I (SP-24) was an armed yacht that served the United States Navy as a patrol vessel from 1917 to 1919.
USS Katherine K. (SP-220) was a United States Navy patrol vessel and tug in commission from 1917 to 1919.
USS St. Sebastian (SP-470) was a United States Navy patrol vessel in commission from 1917 to 1919.
The second USS Sylvia (SP-471), later USS SP-471, was a United States Navy patrol vessel in commission from 1917 to 1919.
USS Fli-Hawk (SP-550) was a United States Navy patrol vessel in commission from 1917 to 1919.
The first USS Moosehead (ID-2047), later the fourth USS Porpoise (YFB-2047), was a steamer that served in the United States Navy from 1918 to 1930.
USS Mary B. Garner (SP-682) was a United States Navy minesweeper in commission from 1917 to 1919.
USS McKeever Brothers (SP-683), sometimes written as USS McKeever Bros., was a United States Navy patrol vessel and minesweeper in commission from 1917 to 1919.
USS See W. See (SP-740) was a United States Navy patrol vessel in commission from 1917 to 1919.
USS Arvilla (SP-752) was a United States Navy patrol vessel in commission from 1917 to 1919.
USS Jolly Roger (SP-1031) was a United States Navy patrol vessel in commission from December 1917 or early 1918 until November 1918.
USS Anemone IV (SP-1290) was a United States Navy patrol vessel in service from 1917 to 1919.
HMS Porpoise was an Acasta-class destroyer of the Royal Navy, which was built by Thornycroft between 1912 and 1914. Porpoise served through the First World War, taking part at the Battle of Jutland in 1916, where she was damaged. In 1920, she was sold to the Brazilian Navy serving under the name Alexandrino de Alencar and was renamed Maranhão in 1927. Maranhão remained in service when Brazil entered the Second World War, being used for patrol and convoy duties. She was disposed of in 1945.
United States