When two gleaming bronze guns, bearing the arms of England and Spain and the date 1556, emerged from the sea in February 1971, the City of Derry Sub-Aqua Club knew for certain that they had rediscovered La Trinidad Valencera after a silence of 400 years. This massive Venetian merchant ship, hi-jacked in Sicily and forced to join the ill-fated Spanish Armada, had limped, battered and sinking, into a remote bay in Donegal on 12 September 1588. Magnus Magnusson tells the story of the club's trials, tribulations and triumphs over the last three years as a group of enthusiastic amateur divers came to terms with one of the most important wrecks in the British Isles and a momentous historical discovery. Re-aired 26 December 1975