The RFA ensures the Royal Navy is supplied and supported by providing fuel and stores through replenishment at sea, transporting Royal Marines and British Army personnel, providing medical care and transporting equipment and essentials around the world.

RFA vessels are commanded and crewed by these sailors, augmented with regular and reserve Royal Navy personnel who perform specialised functions such as operating and maintaining helicopters or providing hospital facilities.

As of late 2024, the RFA was suffering from severe manpower shortages resulting in only 6 of 11 vessels being able to be crewed on a regular basis.

Since the Royal Navy of that era possessed the largest network of bases around the world of any fleet, the RFA at first took a relatively minor role.

World War II also saw naval ships staying at sea for much longer periods than had been the case since the days of sail.

The auxiliary fleet comprised a diverse collection, with not only RFA ships, but also commissioned warships and merchantmen as well.

The RFA performed important service to the Far East Fleet off Korea from 1950 until 1953, when sustained carrier operations were again mounted in Pacific waters.

As the network of British bases overseas shrank during the end of the Empire, the Navy increasingly relied on the RFA to supply its ships during routine deployments.

[citation needed] In July 2008, the RFA was presented with a Queen's Colour, an honour unique to a civilian organisation.

All Royal Fleet Auxiliaries are built and maintained to Lloyd's Register and Department for Transport standards.

These figures exclude the merchant navy vessels under charter to the Ministry of Defence performing sealift and fuel provisioning roles.

[14] RFA Fort Victoria is a 'one-stop' replenishment ship, capable of providing under way refuelling and dry cargo (i.e. rearming, victualling and spares).

Two ships of the Fort Rosalie class also provided dry stores replenishment but were placed into extended readiness in 2020.

They are capable of operating and supporting Merlin and Lynx Wildcat helicopters, both of which are significant weapons platforms.

The presence of aviation facilities on RFA ships allows for them to be used as 'force multipliers' for the task groups they support in line with Royal Navy doctrine.

In the interim, the white paper had proposed to upgrade one of the Bay-class vessels with permanent hangar facilities in order to carry out the littoral strike role.

However, Minister Quinn indicated that her functions are projected to be taken over by the new MRSS vessels, approved for acquisition in the 2021 defence white paper.

[50] In February 2023, the vessel identified for this role - MV Topaz Tangaroa - was acquired and in October 2023 entered service as RFA Proteus.

She was purchased for some £70 million and was converted to act as a mothership for autonomous systems and have military communications and light defensive armament added.

[58][59] Up to three additional ships, either new-build vessels or commercial conversions, are planned for eventual acquisition in the mine countermeasures command and support role.

These ships are Merchant Navy vessels leased to the Ministry of Defence (MoD) as and when needed and as such are not part of the RFA.

For ratings below the rank of Petty Officer, this uniform is a single breasted tunic fastened with four RFA buttons, with flapped chest pockets and hip pockets; white shirt and black tie, and a dark blue beret and black leather shoes.

RFAPCS is distinguished from its RNPCS counterpart by the RFA blue ensign and 'ROYAL FLEET AUXILIARY' tape replacing the white ensign and 'ROYAL NAVY' tape worn on the left arm and left chest pocket respectively.

Junior ratings may also wear an RFA badged baseball cap in this order of dress, whilst undertaking courses at Royal Navy establishments.

Manpower was said to have dropped by 5 per cent from 2021 to 2022, contributing to the reduced availability, and even potential redundancy, of some vessels.