The Isles-class trawlers were a class of naval trawler used by the Royal Navy, Royal Canadian Navy and Royal New Zealand Navy during World War II. The type comprised 197 vessels built between 1939 and 1945 in the nearly identical Isles, Dance, Tree and Shakespearian classes. Generally similar to the Castle class naval trawlers of 1916-18, though somewhat larger, they were mainly used on minesweeping and harbour defence duties. Most were armed with one 12-pounder gun (76mm) and three or four 20 mm Oerlikon AA guns with 30 depth charges. In the Dance class a 4-inch AA gun (102 mm) was fitted in place of the 12-pdr, and there were six 20 mm Oerlikons in Annet, Bressay, Damsay, Fiaray, Foulness and Lindisfarne. Four of the trawlers were given 'Bird' names when converted to controlled minelayer