them overnight. Dive boats which provide sleeping accommodation are generally referred to as "liveaboard" boats. Generally a professional crew operate the boat. The boat provides shelter from the weather and is likely to have various facilities such as a toilet (called the "head") and a small kitchen (called a "galley"), to cater for the guests and crew. Day-boats may have a saloon where divers can relax on upholstered benches, and one or more dining tables. Many day boats also have an uncovered sun-deck, and a shaded area, for divers wishing to be out in the open air. The boat will usually have a diving air compressor, oxygen first aid, a VHF radio, a GPS and possibly gas blending facilities. A day boat would generally be used to transport divers to multiple dive-sites (typically between one and three sites) during the same day, or multiple dives at the same site, with surface rest and refreshment periods between them. The divers usually enter the water by stepping off a dive platform or the side of the boat, and return on board using a ladder or a lift. In some cases a smaller "tender" is used to carry divers to and from less accessible sites, and to rescue divers who are in difficulty or who drift away from the boat. Liveaboard On these commercially operated boats, the divers live and sleep on board and dive from the boat for periods of a few days to several weeks. A professional crew navigate and operate the boat. In addition to the usual domestic facilities expected by hotel guests, the boat will have a diving air compressor and emergency oxygen. Some have gas blending facilities and a few even carry a recompression chamber. The divers enter the water by stepping off a dive platform or the side of the main deck, and return to the boat using a ladder or a mechanical lift platform. Divers may also transfer to and from the dive site in a tender which is carried on, and launched from, the liveaboard boat. Liveaboards used on the West Coast of Thailand and in the Red Sea tend to be up to long and have: The lowest deck, which is for the engine and stores. The lower deck, which is all or mostly cabins for the passengers, usually two passengers per cabin. At the stern, a small diving deck with diving ladders. The