Anatomy of a DPV
Controls: Most models use a trigger mechanism to activate propulsion. Other user interfaces can include speed control, lights and camera attachments.
Propeller: Safety is increased with protective housings to prevent accidental appendage intrusion. Some technical-diving models, however, have open designs to reduce drag and increase performance.
Battery: Power sources range in material from nickel-cadmium to lithium-ion, offering a range from as little as 15 minutes to several hours. And it’s all sealed with thick O-rings that must be carefully inspected and lubricated after every charge.
Buoyancy: To suit the diver’s purpose, most models can be adjusted from slightly buoyant to prevent loss, to completely neutral for maximum efficiency and slightly negative for stable parking.