In the realm of maritime defense, the US Navy stands out with a large, varied surface fleet with 16 ship classes -- a formidable force and the most capable in the world.

The foundation of the Navy's power lies in its diversity. The Navy's wide range of vessels is suited to various purposes -- including combat, coastal patrol, amphibious operations and mine clearance.

The varied fleet includes amphibious assault ships, aircraft carriers, mine sweepers, cruisers, destroyers, littoral combat ships, amphibious transport docks, patrol ships, dock landing ships, mine countermeasure ships, command ships and others.

The fleet's diverse capabilities make it ready to confront a variety of threats and challenges in today's complex security landscape and to support key allies throughout the world.

As of July, the US Navy had a deployable combat force of 299 vessels.

There are plans to make the fleet even larger. The Navy's 30-year shipbuilding program, released in 2020, lays out plans to expand the fleet to at least 355 ships by 2049.

The total US Navy fleet in 2021 was almost 6 million tons, according to a 2021 analysis by the Center for Strategic and International Studies.

Aircraft carriers and amphibious ships

That sizable total includes the largest aircraft carrier fleet in the world, with 11 super carriers in service.

The hulking warships serve as mobile air bases at sea and can allow US forces to fly into areas swiftly, without the complicated process of gaining permission to set up and land in neighboring nations.

The Navy's aircraft carriers include the largest ships in the world, the Nimitz and Ford class aircraft carriers.

The 10 Nimitz class aircraft carriers are the backbone of the Navy.

Each is designed for a 50-year service life, with a single mid-life refueling. Some have gone beyond the planned service life to 52 or 55 years. The carriers' nuclear reactors enable the ships to operate for over 20 years without refueling.

Refueling complex overhauls are performed at the mid-point of a carrier's 50-plus-year lifespan, and includes the replacement of expended nuclear fuel with new fuel and upgrades to propulsion equipment, infrastructure, and combat support systems.

The newest carrier in the fleet is the Navy's first-in-class, nuclear-powered USS Gerald R. Ford (CVN-78).

The Ford is powered by two highly enriched uranium nuclear reactors with four shafts, capable of a top speed of about 30 knots (55.6km/hour).

Additionally, the Navy has another two dozen flat-decked amphibious ships that could be considered carriers in their own right.

Amphibious warships are able to sail in harm's way and provide a rapid buildup of combat power ashore in the face of opposition. Because of their inherent capabilities, these ships have been and will continue to be summoned to support humanitarian and other contingency missions on short notice.

The America class amphibious assault ship can carry various aircraft, such as the F-35B, AV-8B Harrier II, V-22 Osprey and the AH-1Z Viper.

The Whidbey Island class and Harpers Ferry class dock landing ships that typically accompany such assault ships can transport Marines and their vehicles for amphibious operations, including air-cushioned landing craft.

Destroyers and cruisers

Beyond its impressive carrier fleet, the US Navy surface fleet boasts a substantial complement of destroyers and cruisers.

With a total of 73 destroyers, including the Arleigh Burke and Zumwalt class ships, and 17 cruisers, the Navy possesses formidable multi-mission offensive and defensive capabilities.

These ships can operate independently or as part of carrier strike groups, surface action groups, amphibious ready groups and underway replenishment groups, providing a versatile and responsive force capable of countering a wide range of threats.

The Arleigh Burke class guided-missile destroyers can perform anti-air, anti-submarine or surface warfare.

For their part, the Zumwalt class destroyers are larger than the Arleigh Burke class but have innovative technology allowing them to shrink their radar signatures to that of a fishing boat.

Meanwhile, Ticonderoga class guided-missile cruisers are multi-role warships that can launch missiles, perform anti-submarine missions and conduct interdiction or escort operations.

Altogether, the Navy's surface fleet is the most powerful and globally influential naval force in the world, and its extensive range of ship classes ensures unrivaled power projection capabilities.