OVERVIEW: The Drifting Contact Mine is a free-floating naval explosive device designed to damage or destroy surface vessels upon physical contact. It relies on ocean currents and surface drift to move within a designated maritime area without mooring.

DETAILS: Drifting contact mines consist of a buoyant, watertight casing filled with high explosive and fitted with protruding contact horns or chemical detonators. When these horns are struck by a ship’s hull, the fuze triggers detonation. These mines are not anchored and rely entirely on oceanic drift, making them unpredictable and indiscriminate. Historically deployed in large numbers during both World Wars, drifting mines are now restricted or banned under international law due to the long-term threat they pose to civilian and military vessels alike. Nevertheless, they have been used in various conflicts to deny or threaten maritime routes. Their deployment is typically from surface ships, submarines, or aircraft.

FUNCTION: After deployment, the mine floats freely at or near the surface, carried by currents. On contact with a vessel, the pressure-sensitive or chemically-activated horns detonate the charge, causing structural damage to hulls.

NOTE:
IOC: 1915 (first widespread use by Imperial Germany during World War I)
Operators: Historically used by Germany, Soviet Union, Japan, United States, China
Platforms: Surface ships, submarines, aircraft
Conflict used in: World War I (1915–1918), World War II (1939–1945), Korean War, Vietnam War, Iran–Iraq War

SOURCE: U.S. Navy Ordnance Pamphlet OP 888 ; International Mine Warfare Handbook ; Jane’s Mines and Mine Clearance ; Naval War College Review ; https://www.navy.mil ; https://www.janes.com