The Naval Service is dominated by the Royal Navy, and operates primarily from three bases in the United Kingdom where commissioned ships are based; Portsmouth, Clyde and Devonport, the last being the largest operational naval base in Western Europe. As of January 2024, there were nearly 100 vessels in service with the various branches of the Naval Service, plus about 100 additional vessels operated by the supporting Serco Marine Services. These vessels included: 68 commissioned ships of the Royal Navy, 17 principal landing craft of the Royal Marines, 13 auxiliary ships of the Royal Fleet Auxiliary and about 100 supporting Marine Services vessels.^[5] Additional vessels are under charter to the Ministry of Defence. As of 2022, HM Naval Service (Royal Navy, Royal Marines, Royal Fleet Auxiliary and Naval Careers Service) employed about 39,500 regular and reserve personnel.^[6][7][8][9]


In 2020, the First Sea Lord announced that the 'Naval Service' will informally be known as the 'Royal Navy'. The Royal Navy was made a colloquial name for the Naval Service as part of a transformation programme with the approval of the Navy Executive Committee to reflect the strength of the Royal Navy brand and assist with unifying the force.^[10][11]


The total displacement of the Royal Navy and the Royal Fleet Auxiliary is, as of January 2024, in excess of 762,200 tonnes, while the combined displacement of Royal Marine landing craft is approximately an additional 2,200 tonnes.