 Other naval units involved were two Hunt class destroyers , HMS Tynedale ( <unk> ) and Atherstone ( <unk> ) , which would accompany the force to and from the French coast and remain out at sea during the raid . A Motor Gun Boat ( 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 ( 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 . 
