Discovering The Truth About Gear
What is an Underwater Propulsion Vehicle
Scuba and rebreather divers are using an underwater propulsion vehicle, or called diver propulsion vehicle (DPV) or underwater scooter, as one of their diving equipment items that increases their range underwater.
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. When the design was made for this vehicle, it was in such a way that the vehicle should not harm the diver, diving equipment, or marine life, and that it cannot be accidentally started nor will run away from the diver, and that the vehicle has to remain neutrally buoyant while it is used underwater.
DPVs are typically used in cave diving and technical diving where the vehicles serve as a help in moving bulky equipment and thus allowing the diver to make better use of the limited underwater time as stated by the decompression requirements for deep diving. To make a DPV more useful, some accessories can also be mounted to the DPV accessory board. These accessories are dive gears like 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.
The operation of DPV requires more than situational awareness than mere simple swimming since its operation requires simultaneous depth control, buoyancy adjustment, monitoring of breathing gas and navigation.
There are several types of DPV, and the most common type is that which tows the diver while holding onto the handles on 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.
Another type of DPV is called manned torpedoes which are fish-shaped vehicles where one or more divers can sit astride or in hollows inside.
Described as a submersible rigid-hulled inflatable boat, this another kind of DPV is called a subskimmer that is powered by a petrol engine if on the surface, and when submerged, the petrol engine is sealed, and the vehicle then runs on battery-electric thrusters that are located ona a cross-arm that is steerable.
Note that as DPVs get bigger, they are now merged into submarines. Small submarines are called wet subs where the pilot’s seat is flooded and thus has to wear a diving gear.
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