Q-ships, also known as Q-boats, decoy vessels, special service ships, or mystery ships, were heavily armed merchant ships with concealed weaponry, designed to lure submarines into making surface attacks. This gave Q-ships the chance to open fire and sink them. The use of Q-ships contributed to the abandonment of cruiser rules restricting attacks on unarmed merchant ships and to the shift to unrestricted submarine warfare in the 20th century.
USS Asterion was a Q-ship of the United States Navy named for Asterion, a star in the constellation Canes Venatici.
USS Atik (AK-101) was a Q-ship of the United States Navy named for al-Atik, a double star in the constellation Perseus. Her twin sister ship was Asterion.
USS Big Horn (AO-45/WAO-124/IX-207) was a Q-ship of the United States Navy named for the Bighorn River of Wyoming and Montana.
USS Threadfin (SS-410), a Balao-class submarine, was the only vessel of the United States Navy to be named for the threadfin.
The first USS Thomas (DD–182) was a Wickes-class destroyer of the United States Navy that entered service just after World War I.
USS S-48 (SS-159) was the first submarine in the fourth group of S-class submarines of the United States Navy.
USS Tide (AM-125) was an Auk-class minesweeper acquired by the United States Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing.
USS Finch (AM-9) was a Lapwing-class minesweeper acquired by the U.S. Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing. Finch was named for the finch, and is strictly speaking the only U.S. vessel named for such.
USS Albatross (AM-71) was an Albatross-class minesweeper of the United States Navy during World War II.
USS Hawk (AM-133) was a Hawk-class minesweeper of the United States Navy during World War II.
The second USS Ibis (AM-134), was a Hawk-class minesweeper of the United States Navy during World War II.
USS Cymophane (PYc-26) was a Cymophane-class patrol yacht acquired by the United States Navy early during World War II. She was used for patrol, escort, anti-submarine, and rescue operations along coastal waters.
USS Marabout (AMc-50) was an Accentor-class coastal minesweeper acquired by the U.S. Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing.
USS Venture (PC-826/PYc-51) was a patrol boat acquired by the U.S. Navy for the task of patrolling the coastal waters of the New York coast during World War II. Her primary task was to guard the coastal area against German submarines. For this reason, she carried depth charges.
Naval trawlers are vessels built along the lines of a fishing trawler but fitted out for naval purposes; they were widely used during the First and Second World Wars. Some—known in the Royal Navy as "Admiralty trawlers"— were purpose-built to naval specifications, others adapted from civilian use. Fishing trawlers were particularly suited for many naval requirements because they were robust vessels designed to work heavy trawls in all types of weather, and had large clear working decks. A minesweeper could be created by replacing the trawl with a mine sweep. Adding depth charge racks on the deck, ASDIC sonar below, and a 3-inch (76 mm) or 4-inch (102 mm) gun in the bow equipped the trawler for anti-submarine duties.
USS Anderton (SP-530), originally to have been USS Raymond J. Anderton (SP-530), was a patrol vessel and minesweeper that served in the United States Navy from 1917 to 1919.
The first USS Courtney (SP-375) was a patrol boat and minesweeper in commission in the United States Navy from 1917–1919.
USS Valiant (PYc-51), originally USS PC-509, was a United States Navy patrol vessel in commission from 1941 to 1944.
HMCS Wolf was an armed yacht of the Royal Canadian Navy during World War II that saw service on the British Columbia Coast of Canada. Constructed in 1915 as the yacht Wenowah, with the US entry into World War I, the vessel was taken into United States Navy service as USS Wenonah (SP-165) as a patrol ship. The vessel escorted convoys between the United States and Europe and between Gibraltar and Bizerte, Tunis and Genoa, Italy. After the war, Wenonah was loaned to the United States Coast and Geodetic Survey for three and a half years before being sold to private interests in 1928. In private ownership, the vessel was renamed at least twice, including Stranger and Blue Water.
United States