Amphibious assault ship in the context of "Carrier-based"

Naval aviation is the application of military air power by navies, either from warships that can embark aircraft (e.g. aircraft carriers, amphibious assault ships and aircraft cruisers) or from coastal naval air stations.It often involves navalised aircraft, specifically designed for naval use.Seaborne aviation encompasses similar activities not restricted to navies, including marines and coast guards, such as in U.S. naval aviators. As with most army aviation units, naval aviation units are generally separate from a nation's dedicated air force.

Naval aviation operations are typically projected by way of carrier-based aircraft, which must be sturdy enough to withstand the demands of shipborne operations at sea. They must be able to take off from a short runway (typically the flight deck of an aircraft carrier) and be sturdy and flexible enough to come to a sudden stop when landing; they typically have robust folding or swinging wings that reduce the occupied space and thus allow more of them to be stored in below-decks hangars and limited parking spaces on flight decks. These aircraft are designed for many tactical purposes, including aerial combat, airstrike/close air support, anti-submarine warfare, early warning, search and rescue, matériel transport, weather observation, patrol and reconnaissance, and wide-area command and control duties.

This is a list of aircraft carriers which are currently in service, under maintenance or refit, in reserve, under construction, or being updated. An aircraft carrier is a warship with a full-length flight deck, hangar and facilities for arming, deploying, and recovering aircraft. The list only refers to the status of the ship, not availability or condition of an air wing. This includes helicopter carriers and also amphibious assault ships, if the vessel's primary purpose is to carry, arm, deploy, and recover aircraft.

A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several operational roles from search-and-destroy to ocean escort to sea denial.

The term "cruiser", which has been in use for several hundred years, has changed its meaning over time. During the Age of Sail, the term cruising referred to certain kinds of missions—independent scouting, commerce protection, or raiding—usually fulfilled by frigates or sloops-of-war, which functioned as the cruising warships of a fleet.

A carrier-based aircraft (also known as carrier-capable aircraft, carrier-borne aircraft, carrier aircraft or aeronaval aircraft) is a navalised aircraft designed for seaborne flight operations from aircraft carriers. The term is generally applied only to shipborne fixed-wing aircraft that require a runway of some sort for takeoff and landing, as VTOL aircraft such as helicopters are inherently capable of adapting to flight operations from a wide variety of ships (not just aircraft carriers) as long as the served vessel is equipped with helipads or a sufficiently spacious deck that can provide a reliable landing area, which include helicopter carriers, amphibious assault ships, aviation-capable surface combatants (cruisers, destroyers, frigates and some corvettes), container ships and even cruiseliners.

Carrier-based aircraft are designed for many purposes including aerial combat, surface attack, anti-submarine warfare (ASW), search and rescue (SAR), carrier onboard delivery (COD), weather observation, reconnaissance and airborne early warning and control (AEW&C). Such aircraft must be able to take off from the short distance available on the carrier's flight deck and be sturdy enough to withstand the abrupt forces exerted by on a pitching deck due to sea waves. Some modern carrier aircraft are designed for catapult-assisted takeoffs and thus also need to be constructed more robust airframes and landing gears that can handle sudden forward accelerations. Arrestor hook is mandatory feature for those designed for CATOBAR or STOBAR landing, while thrust vectoring or tiltrotor nacelles are commonly seen in those capable of V/STOL operations. In addition, their wings are generally larger (thus can generate more lift) than the land-launched counterparts, and are typically able to fold up or swing back for taxiing, pushback and parking in tight quarters.

A landing craft utility (LCU) is a type of boat used by amphibious forces to transport equipment and troops to the shore. They are capable of transporting tracked or wheeled vehicles and troops from amphibious assault ships to beachheads or piers.

A helicopter carrier is a type of aircraft carrier whose primary purpose is to operate helicopters. It has a large flight deck that occupies a substantial part of the deck, which can extend the full length of the ship like HMS Ocean of the Royal Navy (RN), or extend only partway, usually aft, as in the Soviet Navy's Moskva class or in the Chinese Navy's Type 0891A. It often also has a hangar deck for the storage and maintenance of rotorwing aircraft.

Pure helicopter carriers are difficult to define in the 21st century. The advent of STOVL aircraft such as the Harrier jump jet, and now the F-35B, have complicated the classification; the United States Navy's Wasp class, for instance, carries six to eight Harriers as well as over 20 helicopters. Only smaller carriers unable to operate the Harrier, and older, pre-Harrier-era carriers, can be regarded as true helicopter carriers. In many cases, other carriers, able to operate STOVL aircraft, are classified as "light aircraft carriers". Other vessels, such as the Wasp class, are also capable of embarking troops such as marines and landing them ashore; they are classified as landing helicopter docks.

A landing helicopter dock (LHD) is a multipurpose amphibious assault ship that is capable of operating both as a helicopter carrier and as a dock landing ship. LHD vessels are built with a full-length flight deck similar in appearance to a light aircraft carrier to operate VTOL rotorcrafts such as utility/attack helicopters, tiltrotor aircraft (such as the MV-22 Osprey) and VSTOL fixed-wing aircraft (such as the AV-8 Harrier and the F-35B Lightning II), as well as a well dock for launching landing crafts and amphibious vehicles. Some recent designs, such as the Chinese Type 076 class, even support CATOBAR operations for light aircraft and UCAVs via aircraft catapults and arresting gears.

The United States Navy (USN) and the Royal Australian Navy (RAN) use the term as a specific hull classification symbol. Examples of this kind of ship include the USN's Wasp class, French Navy's Mistral class and ships of the Spanish Navy's Juan Carlos I class including those designs based on the class, such as the RAN's Canberra class. Other nations also use the designation for their vessels, such as the Republic of Korea Navy for its Dokdo class. The Type 075 and Type 076 classes of the People's Liberation Army Navy (PLAN), though only regarded as amphibious assault ships in their native China, are considered LHDs in NATO reporting names.

A littoral combat ship (LCS) is a relatively small surface vessel designed for littoral warfare in near-shore operations. There are two LCS ship classes deployed by the United States Navy. The LCS was "envisioned to be a networked, agile, stealthy surface combatant capable of defeating anti-access and asymmetric threats in the littorals", although their ability to perform these missions in practice has been called into question.

Littoral combat ships are comparable to corvettes found in other navies. The Freedom class and the Independence class are the two LCS variants. Each is slightly smaller than the U.S. Navy's earlier Oliver Hazard Perry-class frigate but larger than Cyclone-class patrol ships. Each has the capabilities of a small assault transport, including a flight deck and hangar for housing two SH-60 or MH-60 Seahawk helicopters, a stern ramp for operating small boats, and the cargo volume and payload to deliver a small assault force with fighting vehicles to a roll-on/roll-off port facility. Standard armaments include Mk 110 57 mm guns and RIM-116 Rolling Airframe Missiles. They are also equipped with autonomous air, surface, and underwater vehicles. Possessing lower air defense and surface warfare capabilities than destroyers, the LCS emphasizes speed, flexible mission modules, and a shallow draft.