Descents And Ascents:
DPVs pull you along fast, which means you need to use caution ascending and descending.
If you point yours straight up or down and pull the trigger, you’re going to exceed a safe descent/ascent rate,
and that means unacceptable risk of ear, sinus or mask squeezes, ear drum rupture, lung over expansion injuries and decompression sickness.
You get the picture – don’t do that. (Some manufacturers stipulate that you use their DPVs only for level travel.)
DPVs can take you up and down faster than you might imagine, so it’s important to monitor your depth closely when scootering.
Descending or ascending with a DPV under power requires a very gentle, shallow sloping angle (up or down).
Use your computer or gauges to help you gauge your rate, breathe normally, and equalize normally.
Never ascend faster than 18 meters/60 feet per minute (slower if prescribed by your computer),
and never descend faster than you can equalize comfortably. Don’t neglect safety stops.
If you don’t have room for slow, sloping ascents/descents, make them normally while towing your scooter – not under power.
Keep in mind that scooters are really ideal for horizontal use – when approaching an obstacle,
its usually easier to control your buoyancy and avoid the risks of rapid ascent by going around the obstacle rather than over it.
DPVs And The Buddy System:
When it comes to DPVs, you’ll find you prefer your buddy to have one, too.
When you both have DPVs, the batteries last longer, you go faster and it’s more fun.
Plus, if one of you has a vehicle failure, the other can tow everyone and the vehicle back (or most of the way back) to the exit.
Because you crank along much faster than you can swim, it’s easy to accidentally separate.
One effective way to stay close is for the diver with the slower DPV to lead, with the follower maintaining the same relative position.
This is important so the leader can confirm contact easily and frequently,
and doesn’t inadvertently leave the follower far behind with a dead scooter or some other problem.
In either position, be careful maneuvering near your buddy, other divers and objects – although DPV speeds aren’t that great,
they’re faster than you can swim and the mass of a diver and vehicle has the potential to injure.
It’s important that the lead diver check on the following diver frequently.
And, because it can be difficult to signal while scootering, you may need to establish signals that only need one hand,
or be prepared to stop when you need to communicate.
Sometimes, you may find you’re the only diver with a DPV. Does this mean you don’t get to use it? Not necessarily.
You can tandem ride a DPV if you plan the dive accordingly. For one, you reduce your range and you reduce your speed.
If the DPV conks out, you don’t have another to tow you both back.
When tandem DPVing, plan your dive so you stay within an easy swim of your exit (a good idea in any case).
Ride tandem to cover more area, rather than more distance.
Propeller Entanglement And Obstruction:
Perhaps the most common problem unique to DPV diving is getting something caught in the propeller.
Usually, this is a piece of dive gear, though you can sometimes have problems with kelp or other debris.
You always want to dive streamlined, with nothing dangling or protruding, especially your SPG and alternate air source.
Eliminate all loose ends, dangling straps and unsecured lanyards.
This really pays off with DPV diving because you eliminate the primary entanglement causes; needless to say,
getting your alternate second stage sucked into a DPV prop does neither the DPV nor the alternate any good.
Make a habit o checking your streamlining when scootering, since water drag can pull things loose.
You may also prefer an adjustable alternate second stage that you can desensitize slightly, since streamlining water can cause a slight free flow.
Use caution around thick kelp, water hyacinth or any other heavy vegetation that easily gets pulled into props.
Power down and tow your DPV through such areas, especially when scootering on the surface.
When you ride your scooter, you shouldn’t block normal water flow into the prop, nor should you feel the prop wash coming out.
Doing either hampers your DPVs performance; ride your vehicle as intended by the manufacturer.
If you feel any unusual sound or vibration while scootering, stop because this may indicate something’s wrong.
If you don’t find an immediate cause, tow your scooter to the exit to avoid permanent damage.
