Other naval units involved were two s, and , which would accompany the force to and from the French coast and remain out at sea during the raid. A Motor Gun Boat (the Fairmile C type "MGB 314") was the headquarters ship for the raid, with Commander Ryder and the commanding officer of the commandos on board. A Motor Torpedo Boat (a 70ft Vosper, "MTB 74"), commanded by Sub-Lieutenant Michael Wynn, had two objectives: If the outer Normandie dock gates were open, she had to torpedo the inner dock gates. If the gates were closed she would instead torpedo the gates at the old entrance into the St Nazaire basin.