1 Assault Group Royal Marines (1AGRM) provides the Royal Marines expertise in small boat operations in support of littoral operations, both amphibious and riverine activities. It is based at Royal Marines Poole in Dorset and comprises a number of individual squadrons.
4 Assault Squadron RM providing landing craft support to HMS Bulwark
6 Assault Squadron RM providing landing craft support to HMS Albion
9 Assault Squadron RM providing landing craft support to HMS Ocean
10 Landing Craft Training Squadron
11 Amphibious Test and Trials Squadron RM based at Royal Marines Instow, Devon
1 AGRM also provide the training and expertise for 539 Assault Squadron RM, based in Turnchapel in Plymouth, which provides landing craft amphibious and riverine capability to 3 Commando Brigade Royal Marines. 539 Assault Squadron is named after the famous 539 Assault Flotilla which landed on Gold Beach during the Invasion of Normandy.
Individual squadrons are commanded by a Major and are variously equipped with vessels including hovercraft (LCAC), Rigid Raider motor boats, inflatable raiding craft and landing craft.