Group Two, under the command of Captain Burn, in ML 192, 262, 267, 268, 156 and 177 would land at the old entrance to the St Nazaire basin. Their objectives were to destroy the anti-aircraft positions in the area and the German headquarters, to blow up the locks and bridges at the old entrance into the basin and then to guard against a counter-attack from the submarine base. Group Three was under the command of Major William 'Bill' Copland, who was also the commandos' second in command. They were to secure the immediate area around "Campbeltown", destroy the dock's water-pumping and gate-opening machinery and the nearby underground fuel tanks. All three groups were subdivided into assault, demolition and protection teams. The assault teams would clear the way for the other two. The demolition teams carrying the explosive charges only had sidearms for self-defence; the protection teams, armed with Thompson submachine guns, were to defend them while they completed their tasks.