Submarine

submarine, any naval vessel that is capable of propelling itself beneath the water as well as on the water’s surface. This is a unique capability among warships, and submarines are quite different in design and appearance from surface ships.

Submarines first became a major factor in naval warfare during World War I (1914–18), when Germany employed them to destroy surface merchant vessels. In such attacks submarines used their primary weapon, a self-propelled underwater missile known as a torpedo. Submarines played a similar role on a larger scale in World War II (1939–45), in both the Atlantic (by Germany) and the Pacific (by the United States). In the 1960s the nuclear-powered submarine, capable of remaining underwater for months at a time and of firing long-range nuclear missiles without surfacing, became an important strategic weapon platform. Armed with torpedoes as well as antiship and antisubmarine missiles, the nuclear attack submarine has also become a key element of naval warfare.

Following is a history of the development of submarines from the 17th century to the present. For a history of other warships, see naval ship. For the weaponry of modern attack and strategic submarines, see rocket and missile system.