on 29 October1914. While U 19 was only damaged, the next month Garry successfully sank U 18. The first depth-charge sinking was on 4 December1916, when UC 19 was sunk by Llewellyn.

The submarine threat meant that many destroyers spent their time on anti-submarine patrol; once Germany adopted unrestricted submarine warfare in January 1917, destroyers were called on to escort merchant convoys. US Navy destroyers were among the first American units to be dispatched upon the American entry to the war, and a squadron of Japanese destroyers even joined Allied patrols in the Mediterranean. Patrol duty was far from safe; of the 67 British destroyers lost in the war, collisions accounted for 18, while 12 were wrecked.

At the end of the war the state-of-the-art was represented by the BritishW class.

Inter-war

The trend during World War I had been towards larger destroyers with heavier armaments. A number of opportunities to fire at capital ships had been missed during the War, because destroyers had expended all their torpedoes in an initial salvo. The British 'V' & 'W' classes of the late war had sought to address this by mounting six torpedo tubes in two triple mounts, instead of the four or two on earlier models. The 'V'and 'W's set the standard of destroyer building well into the 1920s.

The next major innovation came with the Japanese Fubuki class or 'special type', designed in 1923 and delivered in 1928. The design was initially noted for its powerful armament of six five-inch (127 mm) guns, together with three triple torpedo mounts. The