The Dover Patrol was a Royal Navy command of the First World War, notable for its involvement in the Zeebrugge Raid on 22 April 1918. The Dover Patrol formed a discrete unit of the Royal Navy based at Dover and Dunkirk for the duration of the First World War. Its primary task was to prevent enemy German shipping—chiefly submarines—from entering the English Channel en route to the Atlantic Ocean, thereby obliging the German Navy to travel via the much longer route around Scotland which was itself covered by the Northern Patrol.