Sailor-turned documentary maker Des Cox owns one of the world's biggest maritime archives: a celebration of the golden years of British shipping.
When he was handed reels of film from the 1920s - film that was about to be thrown away - he expected it to come to nothing. Not least because the film was in an extremely fragile state.
Then - as he inspected the frames - he saw an image that looked familiar. It looked like The Titanic. A lot like The Titanic. It led to the most important discovery of his career. John Ryall went to meet him at his home in Saltdean near Brighton.