Structures have been used in the sea for millennials. More recently, offshore structures have been used for producing different forms of energy, such as oil, gas and wind energy. The first offshore structures for energy production were wooden piers installed on the beach, followed by steel structures placed in water close to the shore. These initial offshore platforms were simple structures fixed to the seabed. Fixed structures were typically built around the wells for protection and to provide a platform where the wells could be maintained and serviced. Design and construction of offshore platforms followed practices from civil and marine engineering. In addition to fixed structures, the oil and gas industry also used floating units for exploration and drilling since its earliest days in the Gulf of Mexico and Middle East. The first floating production was from around the same time, using steel barges on which drilling rigs were installed.