Canadian corvettes at work: LS and MLS of minesweeper HMCS Chedabucto (J-186) speeding by. A freighter is visible in the distant background. Various shots of ships belonging to the convoy from one of the escorting warships. Sequence on men swabbing the decks of the camera ship, carrying out various other duties, working in galley, eating, amusing themselves by playing music, dancing jigs. Cut to group of engineers, faces smudged with soot, looking on. LAS of officer on deck looking through binoculars. GROUND TO AIR LS of Catalina patrol flying-boat in flight. Action stations: men come out of hatch in deck, run to stations, load deck gun, prepare to launch depth charge. Charges are dropped and LS of explosions in water. Shots of freighters in convoy and night views of same, minesweeper "HMCS Chedabucto" patrolling. Silhouettes of bridge, of man on lookout against lighter water.