The officer waving the ship off is my late father, Capt Peter de Neumann, GM; holder of a George Medal and Lloyd's War Medal for Bravery at Sea. It is filmed partly at the New Entrance to Tilbury Docks. My father was widely known as "The Man From Timbuctoo", and was killed in an accident in the docks on 16 September 1972, aged 54. He is credited with the "Truculent Light", a light shown by surfaced submarines, which idea he had following the sinking of HMS Truculent in 1950. He also thought up, and oversaw the installation of the Thames Navigation Service which came into service at Gravesend in 1960.