Original cockleshell canoe
Ferrer plays newly promoted Major Stringer of the Royal Marines, who comes up with a novel idea for a raid. By using collapsible canoes, he believes it is possible for commandos to reach an enemy-held harbour undetected and blow up ships with limpet mines. He is given command of a small group of volunteers.
However, he clashes with his veteran second-in-command, cynical, by-the-book Captain Hugh Thompson (Trevor Howard). The two officers represent the clash of cultures in the Royal Marines in World War II and postwar. Stringer is the enthusiastic promoter of commando operations requiring daring and initiative, but has no experience leading men or operations. Thompson represents the old guard of traditional ship's detachments. Sergeant Craig (Victor Maddern) trains the men following Stringer's directions, but Thompson strongly disapproves of his commander's lax methods. When a test mission ends disastrously, Stringer admits his mistake and turns to Thompson, who soon whips the marines into shape.
Ruddock (David Lodge), one of the men, goes AWOL due to marital problems. Thompson gets to Ruddock's wife first and finds her with her civilian lover, but leaves when they both insult him. He goes to the local pub for a drink and finds the missing Marine. Thompson gives Ruddock enough time to beat up his wife's paramour, then drives him back to camp.
The raid is launched soon afterwards: the canoes and commandos transported to the mouth of the Gironde by the submarine HMS Tuna. As they arrive off the Gironde estuary a depth charge attack by a passing German patrol boat knocks out Ruddock's partner. Thompson, who was not supposed to go on the raid, volunteers to take his place. The raiders then disembark and begin their attack. They face seventy miles of paddling upriver in their Cockle Mk II canoes. After moving by night and hiding by day, only four men reach the target, where they plant limpet mines on a number of ships.
The raid is successful, but only Stringer and Clarke manage to escape. The rest are captured. When Thompson and the other prisoners refuse to divulge what their mission was, they are shot by firing squad, but not before hearing the mines explode.[2]
Who offers to take the place of Ruddock's partner?
Thompson