Merchant Navy
From Tardis Wiki, the free Doctor Who reference
A Merchant Navy was a fleet of ships used for commercial purposes instead of military.
Ace's maternal grandfather, Frank Dudman, was in the British Merchant Navy during World War II. He died at sea during the war. (TV: The Curse of Fenric)
Heather McCrimmon's great-grandpa had been in the Merchant Navy. His ship was torpedoed by a German U-boat in 1944. He was killed. (COMIC: The Submariners)
Behind the scenes
Tom Baker joined the British Merchant Navy at the same time that he took up acting.
When he was fifteen, Gareth Hunt joined the British Merchant Navy.