Western Approaches is a 1944 docufiction film directed by Pat Jackson and was Crown Film Unit's first Technicolor production. It is the fictional account of 22 British Merchant Navy sailors adrift in a lifeboat. They are able to signal by Morse code their position. A nearby U-boat receives the signal along with a friendly vessel which changes course to go to their rescue. The captain of the U-boat decides to wait in ambush with its two remaining torpedoes. Before the rescue ship arrives, the U-boat's periscope is spotted by the lifeboat. The U-boat fires its torpedoes just as the rescue vessel is alerted to the U-boat's presence.