With an array of amphibious ships at their disposal, the US Navy and the US Marine Corps (USMC) are capable of planning and launching a wide array of missions cooperatively and successfully around the world.

The Navy provides three types of amphibious ships to Marine Expeditionary Units (MEUs). With about 2,200 Marines, an MEU is the smallest Marine Air-Ground Task Force (MAGTF) in the US Fleet Marine Force.

The MAGTF is the basic structure for all deployed USMC units, and includes a ground combat element, an aviation combat element and a logistics combat element under a common command element.

The size of a MAGTF depends on its mission, but its structure never varies.

Each MEU is extremely versatile, forward deployed and often first to arrive at a crisis, whether it be natural disaster or combat mission.

In a constant state of readiness aboard amphibious assault ships equipped with fast moving landing craft utility (LCU) boats, landing craft air cushion (LCAC) hovercraft and helicopters, MEUs are able to deploy within six hours, according to Marines.com.

When an MEU deploys, it is supported by an amphibious squadron consisting of an amphibious assault ship (LHA/LHD), an amphibious transport dock ship (LPD) and a dock landing ship (LSD).

The United States maintains the largest and most capable amphibious force in the world, according to the Navy.

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 called upon to also support humanitarian and other contingency missions on short notice.

Amphibious assault ships

Amphibious assault ships -- both general purpose (LHA) and multi-purpose (LHD) -- are the largest of all amphibious warfare ships with a length of 820 feet (249.9 meters) and 844 feet (257.3 meters), respectively.

They project power and maintain presence by serving as the cornerstone of the Amphibious Readiness Group (ARG)/Expeditionary Strike Group (ESG).

They resemble a small aircraft carrier and are capable of vertical/short take-off and landing (V/STOL), short take-off vertical landing (STOVL), vertical take-off and landing (VTOL) tilt-rotor and rotary wing (RW) aircraft operations.

The Tarawa-class LHAs and the Wasp-class LHDs provide the Marine Corps with a means of ship-to-shore movement by helicopter in addition to movement by landing craft.

LHAs are armed with two rolling airframe missile (RAM) launchers, two Phalanx 20mm close-in weapon system (CIWS) mounts, three .50 caliber machine guns and four 25mm Mk 38 machine guns.

LHDs are armed with two RAM launchers, two NATO Sea Sparrow launchers, two or three 20mm Phalanx CIWS mounts, four .50 caliber machine guns and three or four 25mm Mk 38 machine guns.

The aircraft onboard both LHAs and LHDs include 12 CH-46 Sea Knight helicopters, four CH-53E Sea Stallion helicopters, six AV-8B Harrier attack aircraft, three UH-1N Huey helicopters and four AH-1W Super Cobra helicopters.

Each LHA is equipped with four LCU boats or two LCUs and one LCAC hovercraft, while each LHD is equipped with three LCACs or two LCUs.

Amphibious transport dock ships

Amphibious transport dock ships (LPDs) are warships that embark, transport and land elements of a landing force for a variety of expeditionary warfare missions.

LPDs are used to transport and land Marines, their equipment and supplies by LCAC or conventional landing craft and expeditionary fighting vehicles (EFVs) or amphibious assault vehicles (AAVs) augmented by helicopters or vertical take off and landing aircraft (MV 22).

They support amphibious assault, special operations or expeditionary warfare missions and can serve as secondary aviation platforms for ARGs.

LPDs are armed with two 25mm Mk 38 guns, two Phalanx CIWS mounts and eight .50-caliber machine guns, and hold up to six CH-46 Sea Knight helicopters.

Dock landing ships

Dock landing ships (LSDs) support amphibious operations including landings via LCU, LCAC, conventional landing craft and helicopters onto hostile shores.

They transport and launch amphibious craft and vehicles with their crews and embarked personnel in amphibious assault operations.

LSDs are designed specifically to transport and launch LCAC vessels and have the largest capacity for these landing craft (four) of any US Navy amphibious platform.

They also provide docking and repair services for LCACs and for conventional landing craft.

The Harpers Ferry Class LSD has a length of 609 feet (185.6 meters) and is armed with two 25mm MK 38 machine guns, two 20mm Phalanx CIWS mounts, six .50 caliber machine guns and two RAM mounts.