During the Second World War, John Kingsley Cook (1911-94) served in the merchant navy as a wireless officer. He joined in 1940, and went on his first sea voyage, to the United States, in December 1940. His ship was sunk off the coast of Algeria in 1941, the survivors being taken captive and held there until liberated after the Allied landing in North Africa in 1942. He resumed service after a few months recuperating at home, and was discharged in August 1945, when he joined the staff at the Edinburgh College of Art. There, he taught engraving and graphic design and lectured on the History of Art, before being appointed Head of Design in 1960. He retired in 1971.
Throughout the war, Cook drew life at sea and in captivity. He also created a number of retrospective drawings in the 1980s, when he was working on his (as yet unpublished) memoirs. 262 drawings and 2 paintings of his wartime experiences were presented by his family to the National Maritime Museum in 2012.

This scene was drawn on the back of a piece of navigational chart, inscribed: '4 inch gun on the poop of the Empire Guillemot, gunnery practice.' Carrying vital supplies home, the convoys were escorted part of the way across the Atlantic by armed merchant cruisers and submarines. As civilian vessels, the merchant ships had limited armament; just two ‘Tommy guns’ (Thompson submachine guns) and a revolver on Cook’s ship. In his off-watch time, Cook recorded the crew’s firing practice with humour in a lively, cartoon-like sketch. He and the first radio officer, Bert Halliwell, alternated duties in the confined environment of the wireless cabin.