 The convoy reached a position 65 nautical miles ( 120 km ; 75 mi ) off St Nazaire at 21 : 00 and changed course toward the estuary , leaving Atherstone and Tynedale as a sea patrol . The convoy adopted a new formation with the MGB and two torpedo MLs in the lead , followed by Campbeltown . The rest of the MLs formed two columns on either side and <unk> of the destroyer , with the MTB bringing up the rear . The first casualty of the raid was ML 341 , which had developed engine trouble and was abandoned . At 22 : 00 the submarine Sturgeon directed her navigation beacon out to sea to guide the convoy in . At about the same time Campbeltown raised the German naval <unk> in an attempt to <unk> any German lookouts into thinking she was a German destroyer . 
