RFA Tideforce has been officially welcomed into the Royal Fleet Auxiliary at a service of dedication ceremony at Portland Port in Dorset.
The 39,000-tonne fleet replenishment tanker is the latest of what are the four biggest ships in service with the RFA.
RFA Tideforce is the fourth and final vessel of the Military Afloat Reach and Sustainability (MARS) tankers, which includes three sister ships, RFA Tidespring, Tiderace and Tidesurge, all of which are already in service.
The Tide-class tankers will provide replenishment at sea capability and support to the Queen Elizabeth-class aircraft carriers, able to provide for two vessels simultaneously.
Captain Richard Davies, Commanding Officer of RFA Tideforce, says this efficiency is invaluable during moments of vulnerability: "When you’re engaged in underway replenishment, ships can’t defend themselves as well.
"You’re connected up and manoeuvrability is restricted. The ability to do it on both sides effectively halves this time."
Tideforce will provide fuel and water for Royal Navy, NATO and allied warships all around the world and can also operate Chinook, Merlin or Wildcat helicopters from their flight decks.
The delivery of the new ships is a part of the UK Government’s £179 billion plan to provide the Armed Forces with the equipment they need to deliver effective operational support across the globe.
Apprentice CIS Molly Oakley said: "[It] really stands out against the rest of the fleet, and it just looks huge as well."
She will spend most of her time with the carriers, and despite her recent flooding incident, HMS Queen Elizabeth will still deploy later this year with RFA Tideforce, for further sea trials.
Vice Admiral Jerry Kyd, Fleet Commander, said: "There's something like 16,000 valves on board of which one failed - there was a minor flood dealt with very quickly and effectively by the crew.
"Absolutely not a ripple for me at all, and we're looking forward to her going to the United States to do the next phase of the trials with the F-35B Lightning, with of course a Tide-class tanker, so fantastic days ahead."
The Royal Fleet Auxiliary has been providing fuel at sea for the Royal Navy for 113 years and the introduction of Tideforce means they can do it faster and for longer than ever before.