Tag Archives: work of breathing

Recreational vs. technical DPV training – which course is for me?

by Tim Blömeke

DPVs or underwater scooters are becoming increasingly popular, for good reason: They offer the opportunity to cover more ground, save gas by reducing exertion, and improve safety by enabling divers to push against currents. Plus, they’re a lot of fun.

However, the use of DPVs also comes with new ways to get yourself in trouble, so some training is absolutely necessary. For diving in open water, this training comes at two levels, recreational and technical. Below are the main features of each course.

Recreational

This course covers the basics of DPV diving, including

  • Dive planning taking battery life into account
  • Equipment pre-dive preparation and post-dive care
  • Water entry and exit
  • DPV use at the surface and underwater
  • Descents and ascents
  • Depth management in consideration of greater speed of movement
  • Gas monitoring and management while scootering

This course includes instruction on the above subjects on land, as well as two training dives on DPVs. It takes one to two days.

For recreational diving with relatively low-powered scooters, this is adequate. In these dives, a scooter is a non-critical piece of equipment, and (as in rec diving in general) major failures can be handled by simply aborting the dive, making a safety stop, and ascending to the surface. The focus is on having fun while maintaining safety.

Technical

In technical diving, a scooter becomes less of a toy and more of a tool. This course goes into quite a bit of extra detail to account for the additional equipment, planning requirements, tasks, and team procedures. We need to allow for the fact that in tech diving, immediate ascent to the surface is not available as an option for dealing with problems. In addition to the curriculum for the recreational course above, the following is included:

  • DPV rigging for one-handed use
  • User-level maintenance
  • Dive planning with gas, distance, and time constraints; coordination with boat crew
  • Buoyancy and trim
  • Team formation and cohesion, navigation, light signals, separation procedures
  • Managing DPV failures underwater
  • Towing a diver with a failed DPV
  • Gas sharing while scootering
  • Propeller entanglement procedures
  • “Parking” the scooter to enable other tasks like gas switches, DSMB deployment, etc.
  • Environmental considerations, low-impact use, DPV etiquette

Because of the greater scope of subjects, this course has a minimum of four hours of classroom and briefing time. Agency standards require two training dives to a maximum depth of 40 meters.

At Tech Asia however, we feel that two dives is a little on the low side to absorb the skills and build familiarity with the equipment, to the point where students are able to use scooters on technical dives safely without professional guidance. These things can be very distracting initially, and distraction is something we can’t afford. That’s why we offer this course with four dives, which are included in the price. Assuming no issues with skill development, the final two dives will be regular technical dives with DPVs at the student’s current level of training. Course duration is about three days.

So which one is for you?

If you just want to try your hand at something new and have fun with it, then the recreational course is fine. I’ve yet to meet a diver who doesn’t enjoy scootering. 

However, if you plan on using scooters for tech dives, or if you’re the kind of recreational diver who enjoys getting into the nuts and bolts of things, then you may want to consider the more comprehensive, technical course. Note that you don’t necessarily have to be a technical diver to enroll. All of the skills taught can be practiced in recreational equipment configuration.

Carbon Dioxide, part three: Countermeasures

The third part of my series on CO2 has been published by Alert Diver (EU)!

In the first part, I shared a personal close-call story and gave a brief overview of the carbon dioxide metabolism in the human body.

In the second part, we examined the mechanics of carbon dioxide generation and elimination, the complications introduced by depth and dive equipment, as well as the deeply unpleasant and potentially devastating effects of hypercapnia.

In the third and final part, I’m talking about ways and means at our disposal to prevent the kind of problems we spent the first two parts seeking to understand, avoid common mistakes, and become better and safer divers overall.

You can read it here: https://alertdiver.eu/en_US/articles/carbon-dioxide-the-dreaded-enemy-part-3/

Carbon Dioxide, part two: Complications

Excess carbon dioxide can be a source of danger at any level of diving, yet it is barely mentioned in course curricula. Here is part two of my three-part mini series for Alert Diver on the subject, in which I get into the nuts and bolts of how carbon dioxide affects us, and the special considerations we need to take into account when diving.