Few warships get as much attention as aircraft carriers. Massive in size and marvels of engineering, they are essential tools of power projection and symbols of national status.

Today, eight countries — the US, the UK, France, Spain, Italy, India, Russia, and China — operate flattops capable of launching and landing fixed-wing aircraft, but that list grows when amphibious assault ships and helicopter carriers are included.

Amphibious assault ships and helicopter carriers were born out of the island-hoping campaigns of World War II. They allow for the simultaneous deployment of naval infantry and air support.

As multipurpose vessels, they can carry out other missions — notably, anti-submarine warfare.

While not as imposing as full-fledged flattops, amphibious assault ships and helicopter carriers allow smaller navies to wield capabilities usually reserved for larger maritime powers.

The ships of Italy's San Giorgio class have been extensively modified since the first one was commissioned in 1988.

The first two ships, San Giorgio and San Marco, are 436 feet long and displace roughly 7,900 tons of water. The third, the San Giusto, displaces over 8,000 tons.

The ships were designed as amphibious transport docks and have a well deck that can be flooded so amphibious vehicles can exit and enter. They can carry up to 350 soldiers and as many as 36 armored vehicles. They were initially armed with a bow-mounted 76 mm gun, but only the San Giusto still has one.

San Giorgio and San Marco were modified to have full-length decks from which four helicopters — mainly AW101s, AB-212s, or SH-90s — can operate. As a result, they can carry only two landing craft to transport troops and equipment. San Giusto can operate only one helicopter, but it can carry three landing craft.

In 2011, Algeria ordered an improved variant of the San Giorgio class, which was commissioned as Kalaat Béni Abbès in 2014.

At 465 feet long, it's larger than its predecessors, though its deck is only 416 feet. It can carry 450 troops and has two landing spots for AW101 or Super Lynx helicopters. It is also armed with missiles in two vertical launchers and still has the bow-mounted 76 mm gun.

In 1997, China commissioned its first aviation ship, the Type 0891A, also known as the Shichang 82. It is 410 feet long and displaces 9,500 tons. Its deck has landing spots for at least two Harbin Z-9 helicopters.

With no armaments or internal hangar, the Shichang 82 is used almost exclusively for training and transport, but the experience of operating helicopters on it — and intense study of foreign navies — informed the design of China's first real amphibious assault ship, the Type 075 class.

Displacing about 36,000 tons and measuring 778 feet, the Type 075 can carry 30 helicopters, mainly the Z-8, Z-9 and Z-20 models. Russian-made Ka-52K attack helicopters may also be part of the air wing.

Equipped with a floodable well deck, the Type 075s can carry dozens of armored vehicles, about 900 troops, and multiple hovercraft in the Landing Craft Air Cushion class.

Three Type 075s have been completed — two entered service in 2021 — and China plans to have eight in total. There are also reports of interest in a follow-on subclass, the Type 076, which could feature electromagnetic catapults capable of launching fixed-wing drones.

In 1998, the British Royal Navy commissioned the HMS Ocean, which was designed to carry 800 marines and up to 40 vehicles.

Ocean didn't have a floodable well deck, but it was equipped with a stern ramp and four sets of davits on its sides to launch landing craft.

After 20 years in service with the Royal Navy, the ship was sold to Brazil in 2018. It was recommissioned the same year as Atlântico was and given upgrades. In 2020, Brazil announced that Atlântico could operate fixed-wing drones and tilt-rotor aircraft.

Its 660-foot deck can handle at least six helicopters simultaneously, mainly a combination of the EC725 Caracal, S-70B Seahawk, and AS350 Ecureuil models. Its hangar deck can store a total of 18 helicopters.

In 2005, the French navy commissioned the first of its three Mistral-class amphibious assault ships. Each has a 652-foot deck and a full displacement of over 21,000 tons.

The Mistrals can flood their well decks to launch 450 troops, over a dozen vehicles, and four landing craft or two Landing Craft Air Cushion hovercraft.

They can also carry 16 helicopters, six of which can operate on the flight deck at a time. The helicopters most commonly used aboard Mistrals are NH-90s and SA 330 Pumas.

Two Mistrals were built for Russia, but the contract was canceled after Moscow annexed Crimea in 2014. The ships were instead sold to Egypt, which purchased dozens of Kamov Ka-52K, Kamov Ka-29TB, and Kamov Ka-27P helicopters from Russia — helicopters that Russia was planning to use on its Mistrals.

In 2007, South Korea commissioned ROKS Dokdo, the first of two Dokdo-class amphibious assault ships.

At 652 feet long and displacing over 18,000 tons, Dokdo-class ships have flat flight decks and floodable well decks. They can carry about 700 marines, roughly a dozen armored vehicles, and two Landing Craft Air Cushion hovercraft.

Each Dokdo can carry up to 15 helicopters, usually a combination of UH-1Hs and UH-60P Black Hawks. Future air wings are set to include the KAI MUH-1 Marineons.

The second Dokdo-class vessel, ROKS Marado, was commissioned in 2021 and features a number of changes, including vertical launch cells for antiaircraft, anti-ship, and land-attack missiles.

Not to be outdone, Japan in 2009 commissioned the first of two Hyūga-class helicopter destroyers.

Air wings of the ship, which measures 646 feet long and displaces some 18,000 tons, usually consist of three SH‐60K Seahawks and one MCH‐101.

They are also armed with 16 Mk 41 vertical-launch missile cells, two Phalanx close-in weapon systems, and two triple-torpedo tubes.

In addition to the two Hyūgas, Japan is converting its two Izumo-class helicopter carriers into full-fledged carriers that can operate F-35B short-takeoff and vertical-landing jets.

Japan also has three Ōsumi-class tank-landing ships that are primarily tasked with transporting troops, vehicles, and landing craft but can also operate helicopters on their flat decks.

In 2010, Spain commissioned the Juan Carlos I. At 757 feet long, it has a floodable well deck and can carry up to 24 aircraft, about 900 troops, and over a dozen armored vehicles, in addition to hovercraft and landing craft.

The Juan Carlos differs from most amphibious assault ships in that it can operate fixed-wing aircraft, making it more similar to the US Navy's Wasp and America classes.

The Juan Carlos I has a ski-jump ramp and a deck designed to handle the jet blast from short-takeoff and vertical-landing aircraft, like the AV-8B Harrier II jet and V-22 Osprey tilt-rotor aircraft. (The ship could support F-35Bs, but Spain has no plans to buy them.)

Juan Carlos I's air wing is often mixed, with 12 AV-8B Harrier IIs and 12 helicopters, usually a combination of NH-90s, SH-3Ds, AB-212s, and CH-47s.

The Juan Carlos I-class is named for a former Spanish king, but Spain isn't the only country that uses it.

Juan Carlos I is the basis for Australia's two Canberra-class vessels, which were partly built by the same Spanish shipyard, and for Turkey's TCG Anadolu.

The Canberra class kept the ski-jump ramp but can't operate fixed-wing aircraft, carrying 18 helicopters instead. Its air wings are usually made up of MRH-90s and SH-60 Seahawks but can include CH-47s and ARH Tigers.

Turkey's expulsion from the F-35 program meant Ankara couldn't buy F-35Bs, and it plans to make TCG Anadolu a drone carrier instead. The new air wing will include a naval variant of the Bayraktar TB2 with foldable wings and an unmanned fighter jet that's under development.

A Turkish official said the Anadolu would be able to house up to 80 drones, and Turkey plans to add a short-takeoff but arrested-recovery system to the ship to launch and retrieve those drones. Anadolu's air wing may also include the Turkish-built T129 ATAK attack helicopter and the planned Hürjet light attack aircraft.

Anadolu is expected to enter service later this year, and there are plans for a second vessel, TCG Takya.

The US Navy has two classes of amphibious assault ships: the Wasp and America classes.

USS Wasp entered service in 1989. The 844-foot ship can carry up to five M-1 tanks, about 35 light armored vehicles, and roughly 1,800 Marines. It displaces 40,500 tons fully loaded.

Eight Wasp-class ships were built, but one, USS Bonhomme Richard, was lost to fire damage in 2020.

America-class ships, the first of which entered service in 2014, are similar in length but can displace over 44,000 tons. USS America and second-in-class USS Tripoli can also carry roughly 1,800 Marines, but the ships are oriented toward air operations and do not have well decks.

Wasp-class ships can carry about 25 aircraft. A typical air wing consists of six to eight F-35Bs — or up to 20 if they're in what the US military calls the "lightning-carrier" configuration — and a mix of SH-60 anti-submarine helicopters, UH-1Y utility helicopters, CH-53E heavy-lift helicopters, AH-1Z attack helicopters, and MV-22 tilt-rotor aircraft.

The makeup of an America-class ship's air wing depends on its mission, but its "typical air-combat element" includes five F-35Bs, two UH-1Ys, four CH-53Es, 12 MV-22s, two MH-60s, and four AH-1Zs, according to Ingalls Shipbuilding.

Two of the 11 planned America-class ships are in service. The third, the future USS Bougainville, has been under construction since March 2019. Unlike its predecessors, the Bougainville will have a well deck to support amphibious operations, which comes in exchange for a smaller aircraft hangar.