The head of the armed forces joined military top brass, veterans and supporters at a moving ceremony to mark the unveiling of the Copp Memorial.
Chief of Defence Staff General Sir David Richards paid tribute to the bravery of the men and women who served in the secret elite Combined Operations Pilotage Party based on Hayling Island during the Second World War.
It has taken historian Robin Walton three years of campaigning and fundraising to install the 12-ton granite memorial on the seafront.
It was officially unveiled today by Countess Mountbatten in an uplifting ceremony attended by former Coppists.
Hundreds of people attended the event which was presented by actresses Anna Chancellor and Wendy Adams-Evans.
Sir David said: ‘It’s wonderful to be here to remember the brave men of the Combined Operations Pilotage Party whose work did so much to guarantee our freedom today.’
Countess Mountbatten said the memorial was a feather in the cap of Hayling Island.