Some Basic Information about Underwater Propulsion Vehicles
In order to increase the range underwater of scuba and rebreather divers, they use an item of diving equipment called underwater propulsion vehicle, also known as underwater scooter or diver propulsion vehicle or DPV.
The definition of range covers three areas, and these are the restricted amount of breathing gas being carried, the rate of consumption of that breathing gas under exertion, and the time limit as regulated on the dive tables to prevent decompression sickness of divers.
A DPV has several structures, and these are a pressure-resistant watertight casing that contains a battery-operated electric motor, which drives a propeller. Some factors are considered in the design of this vehicle, and these are that it cannot harm the diver, diving equipment, marine life, and that it cannot run away from the diver or accidentally started, and the vehicle is to remain neutrally buoyant while being used underwater.
The usual uses of underwater propulsion vehicle are for cave diving and technical diving, where deep diving needs the help to move big equipment and making divers use better of the limited underwater time based on the decompression requirements. There are also DPV accessories that can be attached onto the DPV accessory board and these can make the DPV more useful. The accessories that can be mounted on to the DPV are compasses, cameras, lobster sticks and even spear guns.
Military applications also use a DPV to deliver combat divers and their equipment at speeds and distances that seem impossible.
Know that the use of DPV is more than simple swimming, but requires depth control, buoyancy adjustment, monitoring of breathing gas, and navigation.
DPV is available in several kinds and the most common type is the one that tows the diver who holds onto the stern or bow. The diver of this tow-behind scooter is placed parallel to and above the propeller wash and this makes the vehicle most efficient.
The next kind of DPV is termed manned torpedoes, shaped like a fish, where the one or more divers can sit typically astride on it or in hollows inside.
The next kind of DPV is called a subskimmer which is described as a rigid-hulled inflatable boat, powered by a petrol engine when on the surface, and when being submerged, the petrol engine is sealed and the vehicle runs on battery-electric thrusters being attached on a steerable cross arm.
As DPVs get bigger, they now turn into the big vehicle called the submarines. There are also small submarines called wet subs, where the pilot’s seat is flooded that then requires the diver to wear diving gear.