Moon pool

Moon pools were first used in the oil drilling industry given the remote offshore locations of oil fields (e.g. sea or in lakes). They have been used for drilling, production, storage and offloading to smaller vessels for transportation of oil. They are also built to pass drilling equipment into the water from a platform or drillship. A moon pool supports the need for drilling pipes to run vertically through the structure or hull. ==The Glomar Explorer==

The Hughes Glomar Explorer was a , ship constructed by the United States in the early 1970s for the recovery of a sunken Soviet submarine from the Pacific seabed. The design of the ship was broadly inspired by oil drilling ships and included a moon pool measuring , into which the submarine was to be recovered, with the bottom of the moon pool then closed off by two gates that would allow the recovered vessel to be examined under cover and in dry conditions. This was a singular use of a moon pool and also possibly the largest dedicated moon pool constructed to date. ==In underwater habitats==

13 Crew in the wet porch/moon pool of the Aquarius habitat Very deep moon pools are used in underwater habitats—submerged chambers used by divers engaged in underwater research, exploration, marine salvage, and recreation. In this case, shown in part D of the diagram, there is no dry access between the chamber and the sea surface, and the moon pool is the only entry or exit to the chamber. Submerged chambers provide dry areas for work and rest without the need to ascend to the surface. This kind of submerged chamber uses the same principles as the diving bell, except they are fixed to the seafloor and may be called a wet porch, wet room, or wet bell. Sometimes the term moon pool is used to mean the complete chamber, not just the opening in the bottom and the air–water interface. The alternative to a moon pool in an underwater habitat is the lock-out chamber, which is essentially like a fixed submarine, maintaining internal air pressures lower than ambient sea pressure down to one atmosphere, with an airlock to enable entry and exit underwater. Underwater habitats may have connected chambers with moon pools and lock-out chambers. Examples of underwater habitats with moon pools • SEALAB II (US Navy) • The Florida laboratory Aquarius, where it is called a wet porch ==In fishing vessels==

Moon pools are becoming increasingly used on longline fishing vessels to allow for hauling of the gear in worse weather conditions. They also reduce the exposure of fish to air, improving quality. Along with bird scaring lines, shooting and hauling gear from a moon pool reduces the risk of fish falling off or being predated by birds. ==Gallery of types==

Catamaran moon pool.png|Cross-section of an open moon pool above the waterline, in a catamaran or a semi-submersible platform Waterline moon pool.png|An open moon pool at the waterline, in a ship or floating structure Airlock moon pool.png|A moon pool below the waterline in an airtight chamber, in a ship or floating structure Chamber moon pool.png|A moon pool below the waterline in an airtight submerged chamber ==See also==