Bugs has been puttering and muttering in and about the noisy room at the back of the dive shop like for-ev-er rearranging rusty piles of goodness knows what, making up languages, and being his usual cheerful self. We have learned not to laugh and point when he is around. Lo and behold, the other afternoon he comes out from the back with an idiot grin, carrying a scuba tank and says, "Thirty one point eight percent".
We got Geezer Gas, and a new compressor!
Enriched Air, Nitrox, EANX, and Safeair are all designations given by different scuba certification agencies for a breathing gas used by scuba divers that is not air, technically. Air, the atmosphere we breathe, is comprised of just a touch less than 21% oxygen, about 78% Nitrogen and a little over one percent of stuff you don't really care about unless you're a welder.
Learning to scuba dive you are taught that being underwater and exposed to pressure brings about issues like nitrogen exposure, nitrogen off-gassing, nitrogen no-decompression limits, spacing your dives to avoid nitrogen loading, and etc. In short, nitrogen is evil.
By increasing the level of oxygen in the air we fill the tanks with (creating Nitrox/Enriched Air/Geezer Gas) we reduce the percentage of nitrogen we breathe, and reduce our nitrogen exposure over the course of the dive. Oxygen, it turns out, not only makes life possible on this planet, it also helps to "scrub" the nitrogen absorbed during scuba diving. By increasing the percentage of oxygen, and with the lessening of nitrogen exposure, diving with nitrox is not only inherently safer, it allows us to extend the time we remain at depth during a dive.
For example; Diving to a depth of 80 feet using good ol' normal air, it is calculated that we can stay there for 28 minutes before we must come to the surface to avoid pressure (nitrogen) complications. However increasing the level of oxygen in the air to 32%, a very common mix, increases the time we can stay safely at depth to 42 minutes! This is great for dive sites like "Texas" here on Roatan, where the depth is consistently 70 to 90 feet and it is so amazing you don't want to leave!
As you can imagine, breathing a mix of gasses that doesn't really occur naturally, and exposing yourself to unusual pressures underwater would present certain issues of the physical and physiological kind. To this end you must be trained in the use of this breathing mix. Here at West End Divers we offer Padi's Enriched Air Certification, that can have trained in the safe use of Nitrox within a day.
Not taught in the course, but generally accepted as fact by divers using Nitrox, is a feeling of increased energy levels after a dive, or even more so after multiple dives. Personal experience has taught that diving three times in one day using air leaves me quite fatigued, willing and able to hibernate for a three hour nap. Forgoing this restful interlude will have me struggling not to fall asleep in my dinner. But three dives in a day on Enriched air and I am like a new man, able to go out and kick up my heals until 8:30! For those of us in the way over thirty crowd it is an energy boon, and for many always the preferred mix. Hence the nickname; Geezer Gas.
Disclaimer: Opinions expressed here are not necessarily those of Padi, West End Divers, or the public in general, but I really think they should be.