Donald Sinden's character was based on the true-life exploits of Sub-Lieutenant Robert Aitken, who died a few weeks after Sinden. In his first autobiography, "A Touch of the Memoirs", Sinden said "I had to re-enact a deed originally performed by Commander Donald Cameron. While his X Craft was being towed across the North Sea, the cable picked up a floating mine which then moved along the cable and made straight for his midget. Cameron rushed forward and, lowering himself over the prow of his craft, managed gingerly to push the mine clear with his feet. Donald was our advisor on the film and told me modestly, "I couldn't think of anything else to do." He was awarded the VC. I wasn't because we used a dummy. But Donald could swim!"