High Quality Content by WIKIPEDIA articles! The North Sea Mine Barrage, also known as the Northern Barrage, was a large minefield laid easterly from the Orkneys to Norway by the United States Navy (assisted by the Royal Navy) during World War I. The objective was to inhibit the movement of U-boats from bases in Germany to the Atlantic shipping lanes bringing supplies to the British Isles. Rear Admiral Lewis Clinton-Baker, commanding the Royal Navy minelaying force at the time, described the barrage as the "biggest mine planting stunt in the world`s history;" but larger fields containing more mines were laid during World War II.