Re: DIY - discussion on building a DIY hookah diving compressor
I'd suggest that SpareAir, in this context, is just one of the many ways dive shops are using FUD to sell more gear and make more profit. There is absolutely no need for "reserve" air if you are working on a recreational sailboat, where you will simply never be more than ten feet below the surface.
If someone can't hold their head together and make a free ascent from ten feet, even on empty lungs, THEY SHOULDN'T BE THERE IN THE FIRST PLACE. Period.
All the extra gear in the world won't help someone who simply should not be there. The trend in the diving industry today is to insist that divers need computers, spare air, and K valves because J (reserve) valves are too dangerous. Bullpuckey! I'd rather have one cam and one spring (the J valve) and know that it is my job to ensure it has not fouled or tripped, than to rely on an extra five pounds of gear, more valving, a second regulator, and a batch of electronics and o-rings and batteries.
Most dive shops can only survive if they can figure out a clever way to get money on a regular basis, more and more every year. Most, not all. Very few dive shops or locations have been around for 30-40 years, they seem to typically last maybe ten years and then dry up and blow away. To stick around, they need a hook (contract with a local college or municipal first responders or a boat and resort location etc.) and even then, everyone is trying to sell more, often at obscene prices.
Like the push to do VIP+ instead of a VIP, all the time, when VIP+ is simply needless on new tanks or steel tanks. "Oh, we do it all the time" shouldn't be my problem, it isn't appropriate and it wastes my money.
Then there are the shops that all "require" a current VIP after a hydro. Require? The DOT requires a visual inspection before the hydro test, and that tester has been trained and certified to do it. So why should an unregulated dive shop require a redundant VIP by some dive association franschisee on top of that? Oh, well, so they can make $15 for a five minute looksee.
Sorry, guys, but while I readily agree with what I was taught, that diving can easily kill you, I also think the whole recreational/sport diving industry is based on FUD not safety. I've had too much crud turn up in tanks that were only filled by certified shops, and heard too much BS from the operators.
And I most firmly think NASDS was right and every other organization was wrong: You've GOT to do panic screening and you've GOT to fail some students, if they just don't have the presence of mind to be safe divers.
DIY hookah? Hell, Jacques Costeau used DIY equipment when he started. Maybe he was lucky as well as skilled. But diving on a sailboat, which is no deeper than diving in most pools, isn't quite the same as maintaining oil drilling equipment in the North Sea.
If the air is of a safe breathing quality, all the rest is details. Except the suitability of the diver.