Francis joined the training ship in 1936 and joined the Royal Navy as a midshipman in 1939. During World War II, Francis served in the Royal Navy on HMS "Manchester", which was in the Mediterranean in July 1941 when she was hit by the first aerial torpedo used in combat by the Germans. He then served on . Following promotion to sub-lieutenant, he served on , which was involved in the escorting of convoys to the Soviet Union. After that ship was sunk in 1942, he served on K248 - River-class Frigate . For his service on the Arctic convoys, he was awarded the Arctic Star and Ushakov Medal. In 1943, he was transferred to K588 . The Colony Class frigate was launched on 10 October 1943, sponsored by Mrs. William Eastham. The ship transferred to the United Kingdom under Lend-Lease on 25 July 1944 and was one of four that sank off Malin Head, County Donegal, Ireland. In November 1945, Francis was given command of the Bar class Boom Defence Vessel Z92 . In 1949, HMS "Barndale" was involved in trials assessing the effect of nuclear blasts on ships. was the subject of these experiments. He was then engaged in mine clearance operations off Sierra Leone until 1951. He was also involved in the search for a missing American nuclear trigger off Orford Ness, Suffolk in 1955. The trigger was recovered.