Convoy (Royal Canadian Navy shooting): sequence on depth charges exploding during anti-submarine sweep, charges shooting out from camera ship, hand pulling trigger of launcher. Cut to MLS of freighter sunken to super-structure. MS of motor torpedo boat speeding across the frame. Two LSs of freighters in convoy, one showing sausage balloon overhead. AERIAL SHOT of convoy, dozens of ships in sight. Boating shot past bows of corvettes in port.