Jackup

A mobile offshore drilling unit (MODU) consisting of a buoyant hull fitted with extendable steel legs. When on location, the legs are lowered to the seabed and the hull is raised ('jacked up') above the water surface on hydraulic or rack-and-pinion systems. Jackups are self-elevating and suitable for water depths up to approximately 150 metres. They are the most common type of mobile drilling rig used in shallow-water regions including the North Sea, Gulf of Mexico, and Middle East.