During the Second World War Milford Haven served in the Royal Navy. In 1942 he was appointed an Officer of the Order of the British Empire for taking the destroyer "Kandahar" through a minefield in an attempt to rescue the cruiser "Neptune". In 1943 he was awarded the Distinguished Service Cross for his work on Malta convoy operations. He retired from the Navy in 1948. He subsequently joined The Castaways' Club, which enabled him to keep in close contact with many of his naval contemporaries.