Ready To Try A Diver Propulsion Vehicle?: DPVs Explained

As recreational diving becomes more popular, innovative inventions are introduced. One of the most fun is the diver propulsion vehicle (DPV) – an invention that has gained acceptance and popularity throughout the diving community. Whether you’re considering trying a diver propulsion vehicle, or if you’re thinking about buying one, you’ll enjoy these basic facts.

What is a DPV?

A diver propulsion vehicle, also known as underwater propulsion vehicle, is a diving tool that increases a scuba diver’s range when he or she is underwater. As a diver, your underwater range is the underwater area you can cover in a single dive. Your own personal range depends on a number of factors, but the most important ones are:

The amount of air you carry on dives with you
The rate at which you consume air. The more air you consume, the shorter the distance you can travel. The opposite is also true.
The time limit specified for the dive, according to dive tables and your computer. As most certified divers can tell you, adhering to time limits will help you to avoid decompression sickness.

How Diver Propulsion Vehicles (DPVs) Work

A diver propulsion vehicle or underwater scooter works a lot like a miniature submarine, as it moves thorough the water via the motion of its propeller. DPV propellers are encased in housings so that they don’t entangle you or your equipment, or restrict your movement in any way. The propeller housing serves another, equally important function: It also ensures that marine life is not adversely affected.

The propeller is operated by a motor, which is generally electric. The motor and its wired components are encased in insulation to prevent short circuiting. When the DPV is underway, all you’ve got to do is steer and maintain speed.

DPVs are designed in a manner that makes it impossible for them to be accidentally operated or accidentally set adrift. In addition, diver propulsion vehicles maintain buoyancy under all conditions.

Types of DPVs

There are a number of diver propulsion vehicle makes, designs, structural set-ups, and manufacturers frequently offer new models. Here is a quick look at some of the most popular types:

Manta Boards are very simple apparatuses which are propelled by a tow vehicle such as a boat or jet ski. Also known as underwater sleds, they have simple handles that an individual holds onto while being propelled through the water.
Diver tugs look a bit like torpedoes with handles that project out from their bodies. When using this type of DPV, divers are towed through the propeller’s wake, which markedly increases efficiency when compared to some other models; for example, riding on top of a DPV increases drag while adversely affecting battery life.
Tow-behind scooters are efficiency-enhanced versions of diver tugs. Divers using this type of DPV wear a special back plate with a D-ring that’s anchored to the DPV. The primary advantage of this style is that the diver is held above the wake at all times, and his or her ability to maintain a horizontal position means that the energy required to thrust forward is kept to a minimum.
Torpedo DPVs are a bit old-fashioned, but they do deserve mention here. To operate this type of DPV, the diver straddles the body or sits in a chamber inside it. More often than not, this type of diver propulsion vehicle accommodates two people. Torpedo-style DPVs work well for low intensity diving, but are generally not considered ideal for traveling long distances.
Subskimmers are larger than average DPVs and are often equipped with gasoline engines. These DPVs are ideal for surface-level towing or for shallow underwater diving expeditions. These types are capable of inflation and deflation as per the requirements of the dive. Once a subskimmer is underwater, its motor is shut off and it operates on battery-powered propellers. This type of DPV isn’t normally used for recreational diving; it was developed for military use but is interesting as a form of underwater propulsion nevertheless.

Dive Planning and DPVs

When planning a dive using a DPV,there are a few basic considerations to keep in mind:

It’s vital that you be familiar with the DPV type, make, and operational procedures before using it underwater. Don’t worry – most of these vehicles are very easy to use.
Speed affects operating time. Pay close attention to gauges and be cognizant of how much time you have remaining. It’s no fun to tow a DPV when in fact you’re the one who is supposed to be getting a ride!

Test the batteries before heading out. Be sure you have 100% power at the beginning of your dive.
Understand time-management strategies for working with the DPV you have chosen. Most of the time, you’ll be able to use a DPV efficiently until it reaches about 40% of its battery capacity.
Any special instructions provided by the DPVs manufacturer must be followed.

Special Precautions

Although DPVs assist in increasing your underwater range, there are some specific precautions which ought to be kept in mind. Although every model comes with a specific list of safety measures and maintenance recommendations provided by the manufacturer, in general the following safety measures should be followed.

Keep hydrocarbon vapors, solvent fumes, and other chemicals away from the DPV motor as these fumes can accumulate in the motor chamber and may ignite or cause an explosion.
If using a DPV with separate propellant, keep it at a safe distance from the motor. Spare propellant cans should be stocked and secured well away from motors and other potential ignition sources.
In DPVs equipped with nose O-rings, follow instructions for removal to the letter. O-rings are typically removed when the DPV is not in use; this prevents hydrogen build up and associated problems.
If a battery was recently charged, wait a full hour to replace nose O-rings.
Never spray a conducting lubricant into the DPVs motor casing as this could lead to fire or cause permanent damage.

Diver propulsion vehicles are fun and they help us to increase our range. However, as with all other diving equipment, knowledge, proper maintenance, and appropriate instruction are key to ensuring your safety, as well as the safety of other divers around you.