Scuba diving specialty certifications every mountain diver should have.
As much as we all love to get into the deep blue, warm water of the tropics, for most of us the majority of our diving takes place near where we live. I feel lucky in that great diving is close by. Lake Tahoe is just 45 minutes up the hill, with Donner Lake and others also nearby.
Ocean diving in places like Monterey Bay can be reached in half a day. What all of these sites have in common is cold water. The rest take place at altitudes typically greater than 4,000 feet. With this in mind, three PADI specialty courses make sense for diver in areas like ours.
PADI Altitude Specialty Course
The thing about diving at altitude is that while air is compressible, water is not. In essence, this means there is a reduction in atmospheric pressure that causes an increase in the pressure gradient between your body tissues and ambient pressure upon surfacing. In short, there’s a greater chance of forming a bubble unless strict guidelines are adheres to.
The PADI Altitude Specialty Course deals with the use of specialized tables and other practices that keep high elevation diving as safe as possible. Other considerations covered are thermal protection and the aquatic environment itself.
PADI Drysuit Specialty Course
Diving at altitude almost always means dealing with colder water than you’ll experience during your tropical vacation. In our case, water temperatures as low as 39 degrees (f) are common all winter, and even during the Summer when the water reaches a balmy 55 degrees, enhanced thermal protection provided by a drysuit is generally the diver’s best choice.
The Drysuit Specialty Course deals with all of the issues involved in diving safely in a drysuit. Like the Altitude Specialty Course, the drysuit specialty also includes making two open water dives. Both courses can take place entirely at the dive site, which generally makes for a fun time.
EANx, or Enriched Air Nitrox Specialty Course
Finally, EANx, or Nitrox as its commonly called is a breathing gas consisting of elevated oxygen levels in combination with reduced amounts of nitrogen. Since your body metabolizes (uses up) the oxygen, the reduced partial pressure of the remaining nitrogen means less of it is available to absorb into your tissues. (That’s not a 100% accurate description of the physics of what’s taking place, but there’s not enough space here to go into detail.)
Basically what this means is that, for a given depth, no-decompression bottom times are dramatically increased. For altitude divers this is very handy because we deal in theoretical depths, which greatly reduces our NDL.
However, diving with enriched air means accepting very strict rules regarding depth and oxygen tolerance, among others. It’s a big deal, but for the disciplined diver, Nitrox can be a godsend. For sea level divers, EANx increases bottom times dramatically as well, making gas consumption the limiting factor on most dives rather than no decompression limits.
So, there it is; the perfect trio of specialty diving courses for the cold water diver at altitude. Not surprisingly, these are also the most popular diving specialties that I teach. If you’re interested in learning more, you can reach me be email (email@example.com) or through Sierra Diving Center, (775) 825-2147. Be safe! Have fun!