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.