This first film in the Canada Carries On series describes the work of the Canadian seamen who manned the supply ships leaving from Canada's eastern ports during World War II. Convoys escorted by Royal Canadian Marine destroyers carried military supplies destined for the Allied Forces. Always on the lookout, the men remained close to their guns, torpedoes and grenades at the ready because the North Atlantic waters were crawling with German U-boats. The film shows the seamen's life onboard, their vigilance through calm and stormy times and how quickly they were able Battle stations when needed.