A "jack-up" is a type of mobile offshore drilling unit used primarily in the oil and gas industry. It consists of a floating platform supported by long legs that can be lowered to the seabed. Once the legs are in place, the platform is raised above the water, allowing drilling operations to take place safely and efficiently in shallow waters. Jack-ups are designed for various drilling activities, including exploration and production. They are often used in areas where water depths range from 10 to 400 feet. The stability and mobility of jack-ups make them a popular choice for companies involved in offshore drilling, such as ExxonMobil and Transocean.