Martin's penchant for low flying contributed to his selection in March 1943 for assignment to the newly formed No. 617 Squadron under Wing Commander Guy Gibson. Martin took part in the "Dambusters" raid on the night of 16/17 May 1943. He piloted the Lancaster bomber AJ-P "Popsie" (officially known as AJ-P "Peter") in the first formation, which was assigned to attack the Möhne Dam in Western Germany. Martin's plane was hit by anti-aircraft fire during the attack, but he successfully accomplished the bombing run and returned. He was awarded a Distinguished Service Order (DSO) for his actions. Martin was considered one of the best pilots in the squadron and was known for his dry jokes and constant good humour that he exhibited at all times, even when he was under considerable pressure.