The survivors of HMS Coventry, which was sunk in the Falklands conflict 29 years ago this month, are gathering in the city for the first time.
Nineteen sailors died when the vessel was hit by Argentinian bombers on 25 May 1982.
The reunion is taking place this weekend and includes a service at Holy Trinity Church on Sunday.
A spokesman for the Royal Navy Association in the city said it was a very special occasion.
Mick Kieron, from the association, said he believed that survivors had only come together officially in recent years.
"We are absolutely delighted that they are coming back to the city, this time for a reunion.
"We have never forgotten. We, in the city, hold a short service every year on 25 May in Holy Trinity Church."
HMS Coventry was one of four Royal Navy warships sunk during the Falklands conflict.
It brought down more aircraft than any other ship during the war but three bombs hit the Coventry and two of them exploded.
Its story is to be made into a film based on a book by commanding officer Capt David Hart Dyke.
In 2007, Capt Dyke talked to the BBC for the first time about his experiences on board the vessel.
He said he knew it was a suicide mission: "I realised why we were doing it.
"If necessary we were the sacrifice rather than other ships which were more important. And that's war. You've got to take risks to win."
The ship capsized in less than 20 minutes.
The remainder of the 300 strong crew managed to escape safely.
The group plan mark the 30th anniversary in Portsmouth.