A flotilla is usually composed of a homogeneous group of the same class of warship, such as frigates, destroyers, torpedo boats, submarines, gunboats, or minesweepers. Groups of larger warships are usually called squadrons, but similar units of non-capital ships may be called squadrons in some instances, and flotillas in others. Formations including more than one capital ships, e.g. men-of-war, battleships, and aircraft carriers, typically alongside smaller ships and support craft, are typically called fleets, each portion led by a capital ship being a squadron or task force (see reference below).