Hull classification symbol in the context of "Hull number"

USS Nimitz (CVN-68) is an aircraft carrier of the United States Navy, and the lead ship of her class. One of the largest warships in the world, she was laid down, launched, and commissioned as CVAN-68, "aircraft carrier, attack, nuclear powered", but she was later redesignated as CVN-68, "aircraft carrier, multi-mission, nuclear-powered", on 30 June 1975, as part of a fleet-wide realignment that year.

The ship was named after World War II Pacific fleet commander Chester W. Nimitz, USN, (1885–1966), who was the Navy's third fleet admiral. She is the only Nimitz-class carrier whose official name is just the surname of the person for whom it is named. Nimitz had her homeport at Naval Station Norfolk until 1987, when she was relocated to Naval Station Bremerton in Washington (now part of Naval Base Kitsap). Following her refueling and complex overhaul in 2001, her home port was changed to Naval Air Station North Island in San Diego County, California. The home port of Nimitz was again moved to Naval Station Everett in Washington in 2012.

A carrier battle group (CVBG) is a naval fleet consisting of an aircraft carrier capital ship and its large number of escorts, together defining the group. The CV in CVBG is the United States Navy hull classification code for an aircraft carrier.

The first naval task forces built around carriers appeared just prior to and during World War II. The Imperial Japanese Navy (IJN) was the first to assemble many carriers into a single task force, known as the Kido Butai. This task force was used with devastating effect in the Japanese attack on Pearl Harbor. The Kido Butai operated as the IJN's main carrier battle group until four of its carriers were sunk at the Battle of Midway. In contrast, the United States Navy deployed its large carriers in separate formations, with each carrier assigned its own cruiser and destroyer escorts. These single-carrier formations would often be paired or grouped together for certain assignments, most notably the Battle of the Coral Sea and Midway. By 1943, however, large numbers of fleet and light carriers became available, which required larger formations of three or four carriers. These groups eventually formed the Fast Carrier Task Force, which became the primary battle unit of the U.S. Third and Fifth Fleets.

USS John F. Kennedy (hull number CV-67) (formerly CVA-67), the only ship of her class, was an aircraft carrier, formerly of the United States Navy. Considered a supercarrier, she was a variant of the Kitty Hawk class, and the last conventionally-powered carrier built for the Navy, as all carriers since have had nuclear propulsion. Commissioned in 1968, the ship was named after John F. Kennedy, the 35th president of the United States. John F. Kennedy was originally designated a CVA, for fixed-wing attack carrier, however the designation was changed to CV, for fleet carrier.

After nearly 40 years of service, John F. Kennedy was decommissioned on 1 August 2007. She was berthed at the NAVSEA Inactive Ships On-site Maintenance facility in Philadelphia, formerly the Philadelphia Naval Shipyard, and, until late 2017, was available for donation as a museum and memorial to a qualified organization. In late 2017, the Navy revoked her "donation hold" status and designated her for dismantling.

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 dock landing ship (also called landing ship, dock or LSD) is an amphibious warfare ship with a well dock to transport and launch landing craft and amphibious vehicles. Some ships with well decks, such as the Soviet Ivan Rogov class, also have bow doors to enable them to deliver vehicles directly onto a beach (like a tank landing ship). Modern dock landing ships also operate helicopters.

A ship with a well deck (docking well) can transfer cargo to landing craft in rougher seas far more easily than a ship which has to use cranes or a stern ramp. The U.S. Navy hull classification symbol for a ship with a well deck depends on its facilities for aircraft—a (modern) LSD has a helicopter deck, a landing platform dock also has a hangar, and a landing helicopter dock or landing helicopter assault has a full-length flight deck.

The United States Navy reclassified many of its surface vessels in 1975, changing terminology and hull classification symbols for cruisers, frigates, and ocean escorts.

The following is a list of United States Navy oilers (hull designations AO, AOE, AOL, AOR and AOT). It does not include gasoline tankers (AOG) or submarine oilers (AOSS).

Oilers are considered to be auxiliaries by the US Navy, and this article's lists are thus a subset of this type of ship. All other auxiliaries can be found at List of auxiliaries of the United States Navy, including the gasoline tankers. Tankers commissioned into the Navy for bulk storage at mobile bases by Service Squadrons during World War II were not classed as auxiliaries but as unclassified miscellaneous vessels (IX).

The escort carrier or escort aircraft carrier (U.S. hull classification symbol CVE), also called a "jeep carrier" or "baby flattop" in the United States Navy (USN) or "Woolworth Carrier" by the Royal Navy, was a small and slower type of aircraft carrier used by the Royal Navy, the Royal Canadian Navy, the United States Navy, the Imperial Japanese Navy and Imperial Japanese Army Air Force in World War II. They were typically half the length and a third the displacement of larger fleet carriers, more-lightly armed and armored, and carried fewer planes. Escort carriers were most often built upon a commercial ship hull, so they were cheaper and could be built quickly. This was their principal advantage as they could be completed in greater numbers as a stop-gap when fleet carriers were scarce. However, the lack of protection made escort carriers particularly vulnerable, and several were sunk with great loss of life. The light carrier (U.S. hull classification symbol CVL) was a similar concept to the escort carrier in most respects, but was fast enough to operate alongside fleet carriers.

Escort carriers were too slow to keep up with the main forces consisting of fleet carriers, battleships, and cruisers. Instead, they were used to escort merchant ship convoys, defending them from enemy threats such as submarines and planes. In the invasions of mainland Europe and Pacific islands, escort carriers provided air support to ground forces during amphibious operations. Escort carriers also served as backup aircraft transports for fleet carriers, and ferried aircraft of all military services to points of delivery.