Japanese aircraft carrier Kaga
Kaga (加賀) was an aircraft carrier built for the Imperial Japanese Navy (IJN) and was named after the former Kaga Province in present-day Ishikawa Prefecture. Originally intended to be one of two Tosa-class battleships, Kaga was converted under the terms of the Washington Naval Treaty to an aircraft carrier as the replacement for the battlecruiser Amagi, which had been irreparably damaged during the 1923 Great Kantō earthquake. Kaga was rebuilt in 1933–1935, increasing her top speed, improving her exhaust systems, and adapting her flight decks to accommodate more modern, heavier aircraft.
Kaga after her modernization, with her distinctive downward-facing funnel
Kaga as completed, with all three flight decks visible
Kaga fitting-out in 1928. This stern view shows the long funnel extending aft below the flight deck, and three 200 mm guns in casemates.
Kaga undergoing post-launch trials off Tateyama, 15 September 1928
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a naval force to project air power worldwide without depending on local bases for staging aircraft operations. Carriers have evolved since their inception in the early twentieth century from wooden vessels used to deploy balloons to nuclear-powered warships that carry numerous fighters, strike aircraft, helicopters, and other types of aircraft. While heavier aircraft such as fixed-wing gunships and bombers have been launched from aircraft carriers, these aircraft have not landed on a carrier. By its diplomatic and tactical power, its mobility, its autonomy and the variety of its means, the aircraft carrier is often the centerpiece of modern combat fleets. Tactically or even strategically, it replaced the battleship in the role of flagship of a fleet. One of its great advantages is that, by sailing in international waters, it does not interfere with any territorial sovereignty and thus obviates the need for overflight authorizations from third-party countries, reduces the times and transit distances of aircraft and therefore significantly increases the time of availability on the combat zone.
Four modern aircraft carriers of various types—USS John C. Stennis, Charles de Gaulle (French Navy), USS John F. Kennedy, helicopter carrier HMS Ocean—and escort vessels, 2002
Comparison of aircraft carriers
French aircraft carrier Charles de Gaulle (rear), and US Navy carrier USS Ronald Reagan conducting joint operations in the Persian Gulf; both with the CATOBAR configuration.
USS Abraham Lincoln (CVN-72) a United States Navy fleet carrier, also often referred to as a supercarrier, seen here underway in 2019 crossing the Atlantic.