cylinders. Types of dive boat The usual classification of recreational dive boats based on operational parameters includes: basic dive boats day boats liveaboards Some overlap of function is possible. Dive boats may be privately owned and operated, or run as a commercial business (generally known as charter boats). The structure, layout and size of a dive boat for any given application may vary considerably according to regional requirements and traditions, and convenience. Basic dive boats These are usually open boats used for short distance, or short duration, trips to dive sites, usually for a single dive or sometimes for a "two tank" trip, either with both dives at the same site, or with the second dive on the way back, or a short distance from the first. They generally have no amenities other than seating and stowage for dive gear, and the divers are usually exposed to wind, spray and sun during the trip. It is common for divers to kit up in their dive suits before boarding, for protection from the weather. It is unusual for the operator to provide refreshments other than bottled drinking water and an after-dive candy. Rigid-hulled inflatable boat Divers only spend a few hours at a time on these fast but exposed boats. The boats are usually relatively small so they can easily be transported on roads and launched at a convenient site depending on the weather. Boats of this size can be launched from slipways or through the surf on suitable beaches. The smaller models are suitable for private use, as they can only transport a few divers. The larger boats can carry enough divers to be viable for professional use. These boats will generally carry basic safety equipment such as marine VHF radio, small boat safety gear, lifejackets and first aid oxygen administration equipment. Space in the boat is limited, and divers generally travel and kit up while sitting on the tubes opposite a central cylinder rack where the fully rigged scuba sets are stowed. Water entry is commonly by simultaneous rolling backwards over the side, and return to the boat by climbing back in over the tubes one at a time after removing the heavy parts of the diving equipment and handing it up to the crew. Some boats have ladders which hook over the tubes to make boarding easier for the less athletic diver, others rely on assistance from the