Convoys: HAS of destroyer escorting freighters. Dim shot of freighters at sea in fog. Dissolve to montage of wartime industries in Canada. Shot of convoy captains in conference. Shipboard shots of rough sea, of crew of camera ship, of other destroyers, of cargo vessels with parts of camera ship in foreground. Shots of action stations being sounded, of crew running to stations. Shots of deck guns of camera ship in action, crew at work topside and in engine room, depth charges being launched, explosions. Shots of storm at sea, of crew off duty.