A light aircraft carrier, or light fleet carrier, is an aircraft carrier that is smaller than the standard carriers of a navy. The precise definition of the type varies by country; light carriers typically have a complement of aircraft only one-half to two-thirds the size of a full-sized fleet carrier. A light carrier was a similar concept to an escort carrier in most respects, however light carriers were intended for higher speeds to be deployed alongside fleet carriers, while escort carriers usually defended convoys and provided air support during amphibious operations.
In World War II, the United States Navy produced a number of light carriers by converting cruiser hulls. The Independence-class aircraft carriers, converted from Cleveland-class light cruisers, were unsatisfactory ships for aviation with their narrow, short decks and slender, high-sheer hulls; in virtually all respects the escort carriers were superior aviation vessels. The Independence-class ships, however, had the virtue of being available at a time when available carrier decks had been reduced to Enterprise and Saratoga in the Pacific and Ranger in the Atlantic. In addition, unlike escort carriers, they had enough speed to take part in fleet actions with the larger carriers. Late in the war, a follow on design to the Independence-class, the Saipan-class, was designed. Two vessels in this class—Saipan and Wright—were completed after the war's end. After very brief lives as carriers, the Saipans were converted to command and communication ships.
The British 1942 design light fleet carrier was a scaled-down version of their Illustrious-class fleet carrier. The design could be built in a yard with little or no experience of warship construction. Although built to merchant standards, the design incorporated better watertight subdivision. Expected to have a lifetime of about three years, the last of the design was taken out of service in 2001. The first eight were built as the Colossus but revisions upgrading the design to handle larger and heavier aircraft led to the remainder being the Majestic class. In the post-war period, the Royal Navy operated a force of ten Colossus class carriers including the two maintenance carriers. In all, fifteen ships were completed from the 1942 design, of which most of the Colossus class and all the eventually completed Majestics were variously sold to Argentina, Australia, Brazil, Canada, France, India and the Netherlands. By 1939 HMS Hermes was being considered as equivalent to a light aircraft carrier, due to her small size and lack of armour.