The Royal Navy defend a convoy of British merchant ships from aerial attack.
Full title reads: "Royal Navy on Convoy".
Various shots of Royal Navy warships sailing in convoy with Merchant Marine vessels.
MS of sailors manning anti-aircraft guns.
More shots of large naval ships. Ships send signals with aldis lamps.
German planes appear overhead. Bombs explode in the water nearby. Anti-aircraft guns fire into the sky. Good MS of newsreel cameraman filming German plane as it is shot down.
More shots of warships in convoy. Aldis lamps signal once again.