 At 23 : 30 on 27 March , five RAF squadrons ( comprising 35 <unk> and 27 <unk> ) started their bombing runs . The bombers had to stay above 6 @,@ 000 feet ( 1 @,@ 800 m ) and were supposed to remain over the port for 60 minutes to divert attention toward themselves and away from the sea . They had orders to only bomb clearly identified military targets and to drop only one bomb at a time . As it turned out , poor weather over the port ( 10 / <unk> cloud ) meant that only four aircraft bombed targets in St Nazaire . Six aircraft managed to bomb other nearby targets . 
