Commercial offshore diving, sometimes shortened to just offshore diving, generally refers to the branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry in places such as the Gulf of Mexico in the United States, the North Sea in the United Kingdom and Norway, and along the coast of Brazil. The work in this area of the industry includes maintenance of oil platforms and the building of underwater structures. In this context "offshore" implies that the diving work is done outside of national boundaries. Technically it also refers to any diving done in the international offshore waters outside of the territorial waters of a state, where national legislation does not apply. Most commercial offshore diving is in the Exclusive Economic Zone of a state, and much of it is outside the territorial waters. Offshore diving beyond the EEZ does also occur, and is often for scientific purposes.
Equipment used for commercial offshore diving tends to be surface supplied equipment but this varies[citation needed] according to the work and location. For instance, divers in the Gulf of Mexico may use wetsuits whilst North Sea divers need dry suits or even hot water suits because of the low temperature of the water.[1]
Diving work in support of the offshore oil and gas industries is usually contract based.[2]
Saturation diving is standard practice for bottom work at many of the deeper offshore sites, and allows more effective use of the diver's time while reducing the risk of decompression sickness.[1] Surface oriented air diving is more usual in shallower water.