Underwater propulsion vehicles also known as diver propulsion vehicles or underwater scooters are diving equipment used by rebreather and scuba divers to improve their range under water. The range is affected by the size of breathing gas carried by a diver as well as the rate at which diver consumes the gas.
Underwater propulsion devices are made of pressure-resistant and waterproof casings that carry motors that are battery-powered. The batteries in the device power a propeller that pushes the device when diving.
The design of a suitable underwater propulsion device should ensure that the diver, marine life, and diving equipment cannot be affected by the propeller. The device should also remain buoyant when being used by the diver.
Underwater scooters as earlier mentioned are used to increase the divers range that in most instances are limited by the amount of gas carried. Typical uses of diving vehicles include technical diving and cave diving where they help use the limited underwater time as well as move bulky equipment.
Military applications of underwater propulsion devices include the movement of equipment and combat divers over long distance at high speeds that in ordinary cases are impracticable.
Scooters, diver-tugs, tow-behind
The most common underwater vehicles are those that tow the diver who holds handles on the bow or stern. The tow-behind propulsion vehicles are efficient since they place the diver above and parallel to the propeller wash. The diver has a harness that also has a D-ring at the front as well as a crotch strap. A releasable metal snap is rigged to the scooter with a tow leash that is clipped on the scooter.
These are fish or torpedo-shaped vehicles used by one or a number of divers in hollows inside or sitting astride them. The first torpedoes were used in World War II, and now similar ones are made for sport or work divers, but they are more streamlined since they do not have warheads.
These are boards that are unpowered and are usually towed by a surface boat using ropes. The diver holds the board and uses an aerofoil to keep it submerged. The boards got their name from the manta ray fish.
In the recent years, underwater propulsion devices have gained popularity and have become household devices used during holidays. The information above will help you in choosing a device of your choice the next time you go shopping for one.