Picket boat
A picket boat is a type of small naval craft. These are used for harbor patrol and other close inshore work, and have often been carried by larger warships as a ship's boat. They range in size between 30 and 55 feet. Patrol boats, or any craft engaged in sentinel duty, are sometimes referred to as picket boats, using "picket" in the generic sense, even if much larger than actual picket boats. United States. The Union's long steam-powered Picket Boat Number One sank the Confederate ironclad "Albemarle" in 1864. (Although named "Picket Boat", this craft  has also been called a steam launch). The boat was armed with a 12-pounder Dahlgren gun and a spar torpedo, of which the latter was employed in sinking "Albemarle". The Union's Potomac Flotilla also employed some picket boats. A number of American warships of the 19th century carried picket boats, such as the (her picket boat was heavily engaged by Spanish small-caliber shore fire during one incident in the Spanish–American War), and others. In the early 1920s, during Prohibition, the United States Coast Guard built a fleet of 103 picket boats to intercept rum runners, supplementing  the larger and more seaworthy cutters and patrol boats. These boats were about long, had no main fixed armament, and cost about (about $ in dollars) to build. A later picket boat, built between 1932 and 1943, was long and also had no large main armament. Britain. A long-serving 19th-century British picket boat, carried on capital ships, was a model introduced in 1867 which saw wide service in World War I and even some limited service in World War II. The typical main armament during most of this boat's service life was a Hotchkiss 3–pounder, adopted  by the Royal Navy in 1886. British pre-dreadnoughts, including and , carried picket boats. The P1000 Class Picket Boat is a current British Royal Navy boat, in length, formerly carried on destroyers but now used only for training. Germany. The "Königsberg"–class cruisers of 1905 and 1915 carried a picket boat; the "Königsbergs" of 1927 carried two. The "Dresden" class of a similar era carried one, as did the "Wiesbaden"–class. Larger ships also carried picket boats: The "Nassau"–, "König"–, and "Bayern"–class battleships, the "SMS Seydlitz", and the "Derfflinger"–class battlecruisers all carried one each.