During the Second World War, designated convoy rescue ships accompanied some Atlantic convoys to rescue survivors from ships that had been attacked. Rescue ships were typically small freighters with passenger accommodation converted to rescue service. This involved enlarging galley and food storage areas and providing berthing and sanitary facilities for approximately 150 men. Preparation for service included the installation of scrambling nets along the sides, and the substitution of boats suitable for open sea work for normal lifeboats. Rescue ships normally included a small operating room for an embarked naval doctor and sick bay staff.

Admiral Sir Max Kennedy Horton, was a British submariner during the First World War and commander-in-chief of the Western Approaches in the later half of the Second World War, responsible for British participation in the Battle of the Atlantic.