News reports often mention a US "amphibious ready group" sailing toward a trouble spot. The phrase sounds technical. The idea behind it is not. It is a self-contained package at sea: a handful of ships plus a force of Marines, ready to act from offshore.
This guide explains what goes into an amphibious ready group, which ships sail in it, and what kinds of jobs it can do.
One group, two parts
An amphibious ready group, or ARG, of the United States Navy has two halves. The first is a naval element, a group of warships known as an Amphibious Task Force. The second is a landing force of US Marines, and at times US Army soldiers as well. In total, the package comes to about 5,000 people. Together, these parts are trained, organized, and equipped to perform amphibious operations. Wikipedia's entry on amphibious ready groups lays out the standard layout.
The three types of ships
A typical group carries one ship of each main type. The first is an amphibious assault ship, an LHA or LHD. It resembles a small aircraft carrier. Its main job is to move troops into a war zone by air, using transport helicopters. In a secondary role, these ships perform sea control and limited power projection missions using AV-8B Harrier II or F-35B Lightning II Marine aircraft. Two classes are in service: the Wasp class and the America class. We covered a connected angle in The U.S. Navy Amphibious Fleet Explained: LHA, LHD, LPD, and LSD.
The second type is an amphibious transport dock, an LPD. It carries troops into the war zone by sea, mostly with conventional landing craft and LCAC hovercraft. The third is a dock landing ship, an LSD, which supports landings onto hostile shores using the same kinds of craft.
The Marines and their aircraft
The landing force is usually a Marine Expeditionary Unit, or MEU. It typically numbers about 2,200 Marines and is usually commanded by a colonel. Its aircraft do much of the daily work. MV-22B Ospreys and CH-53E Super Stallions move people, supplies, and equipment. AH-1Z Viper attack helicopters provide fire support during an assault. UH-1Y Venom helicopters help with command and control, and they add light attack and assault ability of their own.
From disaster relief to major war
The mission list is wide. Amphibious forces must be ready for jobs that range from humanitarian assistance and disaster relief up to major theater war. Because they are sea-based, and because the choice to position or engage them can be reversed, they greatly expand the range of response options leaders hold. Their presence can also show resolve to friends, allies, and rivals alike.
Normally two to three ARGs are forward deployed at any time. One covers the Mediterranean Sea and the Persian Gulf and Indian Ocean area. One or two cover the western Pacific Ocean. One ARG and MEU team, known as Task Force 76 or Expeditionary Strike Group 7, is forward based in Sasebo and Okinawa, Japan. When an ARG deploys, it often sails under the protective umbrella of a carrier strike group, which shields the ships and backs up operations ashore. Readers following this should also see Expeditionary Sea Base Ships Explained: The Navy's ESB and ESD Force.
Conclusion: a fleet within the fleet
An amphibious ready group is best seen as a small, mobile navy of its own. Three kinds of ships carry the Marines, their aircraft, and their landing craft. Roughly 5,000 sailors and Marines make the whole thing work. The mix can handle a storm rescue one month and a serious fight the next, and it can wait offshore until leaders decide to act. That blend of reach and restraint is why these groups stay ready around the clock.
