A Diver Propulsion Vehicle (DPV, also known as an underwater propulsion vehicle or underwater scooter) is an item of diving equipment The fundamental item of diving equipment used by divers is the SCUBA equipment, such as the Aqualung or Rebreather. There are other important pieces of equipment that make diving safer, more convenient or more efficient used by scuba Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater for recreation, commercial or industrial reasons and rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycled exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where humans cannot safely breathe from the atmosphere. In divers to increase range underwater. Range is restricted by the amount of breathing gas Air is the most common and only natural breathing gas. Other artificial gases, either pure gases or mixtures of gases, are used in breathing equipment and enclosed habitats such as SCUBA equipment, surface supplied diving equipment, recompression chambers, submarines, space suits, spacecraft and anaesthetic machines that can be carried, the rate at which that breathing gas is consumed under exertion and the time limits imposed by the dive tables Dive Tables, Decompression Tables or Tables are printed cards or booklets that allow divers to determine for a particular dive profile and breathing gas, the Decompression stops required for that dive in order to avoid decompression sickness in order to avoid decompression sickness Decompression sickness describes a condition arising from the precipitation of dissolved gasses into bubbles inside the body on depressurisation. DCS most commonly refers to a specific type of scuba diving hazard but may be experienced in other depressurisation events such as caisson working, flying in unpressurised aircraft and extra-vehicular.
A DPV usually consists of a battery In electronics, a battery or voltaic cell is a combination of many electrochemical Galvanic cells of identical type to store chemical energy and to deliver higher voltage or higher current than with single cells-powered electric motor An electric motor is a device using electrical energy to produce mechanical energy, nearly always by the interaction of magnetic fields and current-carrying conductors. The reverse process, that of using mechanical energy to produce electrical energy, is accomplished by a generator or dynamo. Traction motors used on vehicles often perform both, which drives a propeller A propeller is a type of fan which transmits power by converting rotational motion into thrust. It can be used to drive an aircraft, ship, or the fluid within a pump. It consists of one or more blades about a central shaft and operates like a rotating screw or wing. A pressure difference between the forward and rear surfaces of the airfoil-shaped. The design must ensure that: the propeller is caged so that it cannot harm the diver, diving equipment The fundamental item of diving equipment used by divers is the SCUBA equipment, such as the Aqualung or Rebreather. There are other important pieces of equipment that make diving safer, more convenient or more efficient or marine life; the vehicle cannot be accidentally started or run away from the diver; and it remains neutrally buoyant In physics, buoyancy is the upward force that keeps things afloat. The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body. This force enables the object to float or at least seem lighter under all conditions.
DPVs are useful for long journeys at constant depth where navigation is easy. Typical uses include cave diving Cave diving is a type of technical diving in which specialized SCUBA equipment is used to enable the exploration of natural or artificial caves which are at least partially filled with water. It is an extension of the more common sport of caving, but is much more rarely practised because of the skills and equipment required, and because of the and technical diving Technical diving is a form of scuba diving that exceeds the scope of recreational diving (although the vast majority of technical divers dive for recreation and nothing else). Technical divers require advanced training, extensive experience, specialized equipment and often breathe breathing gases other than air or standard nitrox where the vehicles help move bulky equipment and make better use of the limited underwater time imposed by the decompression requirements of deep diving The meaning of the term deep diving is a form of technical diving. It is defined by the level of the diver's diver training, diving equipment, breathing gas, and surface support:.
For many recreational divers Recreational diving or sport diving is a type of diving that uses SCUBA equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and DPVs are not useful. Buoyancy In physics, buoyancy is the upward force that keeps things afloat. The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body. This force enables the object to float or at least seem lighter control is vital for diver safety: the DPV has the potential to make buoyancy control difficult and cause barotrauma Barotrauma is physical damage to body tissues caused by a difference in pressure between an air space inside or beside the body and the surrounding fluid if the diver ascends or descends under power. Navigation Navigation is the process of reading, and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks. The word navigate is derived from the Latin "navigare", meaning "to sail". All navigational techniques in visibility of less than 5 metres using a DPV could be difficult. Also, many forms of smaller marine life are very well camouflaged Camouflage is a method of cryptic or concealing coloration that allows an otherwise visible organism or object to remain indiscernible from the surrounding environment through deception. Examples include a tiger's stripes and the battledress of a modern soldier. The theory of camouflage covers various strategies which are used or hide well and are only seen by divers who move very slowly and are very vigilant.
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