A ceremony marking the decommissioning of axed aircraft carrier HMS Ark Royal will take place today.
The fleet flagship was taken out of service as part of the Government's defence review last year.
The navy will not have the capability to fly fixed-wing aircraft from sea for about 10 years until the first of the next generation of aircraft carriers come into service.
The ship's white ensign will be lowered for the final time during the hour-long ceremony on the ship's flight deck.
The ship's last remaining 150 sailors on board will take part in the event at Portsmouth Naval Base in front of about 900 guests including families and former commanding officers.
Civic dignitaries from the ship's affiliated city of Leeds will also be present.
Principal guest will be First Sea Lord Admiral Sir Mark Stanhope who will inspect a guard comprising 30 ship's company.
The service will be conducted by the ship's chaplain, the Reverend Martin Evans, and the Royal Marines Band, Portsmouth, will provide the ceremonial music.
Captain Jerry Kyd, the last commanding officer of HMS Ark Royal who now commands sister ship HMS Illustrious, said Ark Royal had “played a very important role throughout her history and has had considerable success in delivering carrier strike”.
“For me, personally, I have been exceptionally proud to serve as her captain - my very first job after finishing my initial officer training 25 years ago at Dartmouth was in the then brand new HMS Ark Royal.
“It is therefore a great honour for me to have been her last captain.
“I am only too aware that this famous ship and her iconic name mean a great deal to many people, but although Ark Royal will be decommissioned, the new Queen Elizabeth Class aircraft carriers are vastly more capable and will provide the Royal Navy with an exciting future,” Kyd said.
Ark's operations have included playing a pivotal part of the Nato campaign during the Bosnia conflict and, in early 2003, leading the UK's naval forces during Op Telic - the invasion of Iraq, with a fleet of helicopters embarked.
Last November, the Queen visited the ship in Portsmouth as part of Ark Royal's 25th anniversary celebrations.
During its service, Ark Royal clocked up 621,551 nautical miles and made its final entry to Portsmouth on December 3 last year.