What is it like to dive in the murky depths of the ocean? How do you raise the wreck of a ship or aircraft? Here, Kenneth Clark relives his diving experiences from training in the 1950s, to being awarded the Gold Sub Aqua Medal by the Duke of Edinburgh. His achievements include helping raise the Gitana from Loch Rannoch in 1978. At the time, it was the heaviest wreck ever salvaged by amateur divers.