Dive boat

Some features, like convenient access from the water, are common to all dive boats, while others depend on the specific application or region where they are used.

[2] The usual classification of recreational dive boats based on operational parameters includes:[3] Some overlap of function is possible.

[2] The structure, layout and size of a dive boat for any given application may vary considerably according to regional requirements and traditions, and convenience.

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.

The boats are usually relatively small so they can easily be transported on roads and launched at a convenient site depending on the weather.

[1] 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 crew.

These boats are usually fairly fast, maneuverable, seaworthy in surf and rough conditions, and relatively wet and uncomfortable.

They seldom provide any shelter from the elements, and their advantages are that they get the diver to the site and back fairly quickly, are generally good for operation through surf, are usually trailerable and can be launched at slipways and beaches.

These boats are usually less stable than the equivalent inflatable and are not as easy to climb back on board, but are light, durable and economical.

[4] Flush decked boats with transom boarding arrangements are commonly used in areas with generally pleasant weather and sea conditions.

[citation needed] These boats are usually made of rigid materials - such as glass reinforced resin, plywood or aluminium.

Day boats are generally relatively large: typically, between 60 and 90 feet (18 and 27 m) in length, as they must provide some comfort for the passengers for several hours.

The boat will usually have a diving air compressor, oxygen first aid, a VHF radio, a GPS and possibly gas blending facilities.

[citation needed] 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.

[2] In addition to the usual domestic facilities expected by hotel guests, the boat will have a diving air compressor and emergency oxygen.

[citation needed] Liveaboards used on the West Coast of Thailand and in the Red Sea tend to be up to 100 feet (30 m) long and have:[citation needed] The size of a liveaboard can vary considerably, based mainly on the number of passengers carried, the quality of accommodations provided, special equipment carried, and legal constraints for registration.

Basic requirements are the ability to keep station accurately and reliably throughout a diving operation, often in close proximity to drilling or production platforms, for positioning to degrade slowly enough in deteriorating conditions to recover divers without excessive risk, and to carry the necessary support equipment for the mode of diving to be used.

Live-boat operations are considered unacceptably hazardous for surface supplied diving unless a stage or bell is used to keep the divers' umbilicals clear of the vessel's thrusters.

Boats intended for other purposes can usually be used as dive platforms provided that there is reasonably convenient access to the water and enough space to carry the necessary equipment.

Features that make a boat suitable for use by divers are: Basic marine safety equipment for the class of vessel will be required by regional or national legislation, and diving specific safety equipment may also be carried as required by legislation or the diver certification agency to which the boat operator is affiliated.

This will usually include: Basic marine safety equipment: Diving safety equipment: On larger boats additional diving support facilities may also be present: If the freeboard of the boat is too high for the divers to climb back on board unaided, a ladder or other aid must be provided.

The space allowed for walking between platform and boat should take into account the equipment likely to be carried by the diver, such as side mounted cylinders.

[2] Larger vessels, particularly liveaboards, may also provide a camera table and fresh water rinsing facilities for washing gear after the dive.

If there is any significant risk of a diver drifting away from the site, the dive boat should either be ready to slip the moorings at short notice, or have a tender in the water.

Divers may be formally grouped in buddy pairs, surfacing together when the first is low on gas, or more informally, and rely on the divemasters if they have a problem.

This is a fairly substantial natural fibre rope which is deployed from the bottom using a small lift bag to provide the equivalent of a shotline.

The lower end is tied off to the bottom, usually on a wreck, and the diver ascends on the line to avoid being swept away from the site by currents.

A dive boat will not be carrying a decompression chamber to treat a diver with decompression illness - that would normally classify it as a diving support vessel, so treatment would be limited to oxygen therapy with 100% oxygen,[31] first aid emergency life support and transportation to the nearest suitable medical facility, or for operations where the equipment is available, and the risk is assessed as acceptable, technical or scientific divers may choose to do in-water recompression.