Posted by Kendall Raine on January 11, 2002 at 16:53:15:
In Reply to: Re:Let's see... posted by Steve on January 11, 2002 at 15:02:01:
OK, Steve. Good point. New divers don't have much experience with gas management. True. New conditions, depths and work loads compound that problem. Question: What's the best way to deal with this, all things considered? The basis of my logic is that training and experience are the key to gas management in different situations, not gear. Let me explain my thinking. It's not a matter of DIR doctrine, George Irvine, E Pluribus Unum, or anything other than common sense.
1. Gas management is a mission critical skill. There's no getting around it. It must be mastered no matter how many tanks someone carries or the situation of the dive.
2. Divers, and new divers in particular, are vulnerable to equipment and sensory overload. Some deal with it better than others. It's situation specific so that one set of conditions can overwhelm someone who, in other circumstances, would be fine. Adding more gear initially creates stress and distraction until experience with the new gear enables comfort. This is true for everyone but especially so for new divers for whom all the gear is new.
3. Adding a second bottle, plus regulator, plus SPG adds weight, hose management, streamlining, entanglement and drag issues to the equipment configuration. Read: additional mental and physical stress. Additional stress equals higher consumption. (BTW, a Spare Air is not a second bottle. It's a misapplication of the military HEED bottle designed for helicopter evac. I'm talking about a second bottle with enough volume to perhaps be useful-a 14 cu. ft. minimum-big enough to add bulk). Adding a second bottle doesn't solve the gas management issue, either. The only thing the second bottle does with respect to gas management is possibly give an OOA diver a second chance if he can keep his wits about him long enough to deploy it.
4. Isn't a second chance a good thing? I think this is your whole point. The answer is yes and no. A second chance is better than dying. We all agree. But, if the fundamental issue of gas management has not yet been mastered, the second chance can become simply a continuation of the first chance e.g. going OOA on the primary is no big deal because, "hey, I've got my back-up." Or "I don't need to stick as close to my buddy because I've got my back-up." Or, "I can go a little deeper and cut it closer, on consumption and deco, because I've got my back-up." That's a really bad attitude. It's the same reason you can't get near a cave in Florida with a light unless you are cavern/cave certified. Don't think that'll happen? It's complacency and it happens all the time in the technical community. People violate thirds all the time because, "hey, I've always gotten away with it and I have plenty of gas." You've got a second chance with your buddy without the need for extra gear-Wayne's post.
The point is any extra gear is a trade-off issue. Do the positives outweigh the negatives?
This brings me back to teaching gas management. Everyone I dive with can tell me long after the dive what they had in their tanks at the end of the dive-sometimes four different SPG's. That is, what was in their doubles and stages. If they can't, I reconsider diving with them. I always know the pressure in my tank(s), within 200 psi, at any point during a dive. I check my SPG only two or three times during a typical recreational dive. That's just experience and awareness of how deep I've been, how my breathing is, the size of my tank, the temperature, etc. If a dive is stressful, I check more often. How many OW instructors insist their students know what their pressure is (within a margin) during the course, or at the end, of a dive without looking? I know a few who do, but on many of the boats I'm on where classes are present, students need to check their SPG's to fill in log books. I'm not aware that any instructors require their students to know, without looking, what their ending pressure is after every dive as a condition to certification. Perhaps they should.
My point, long winded as it is, is that gas management needs to be taught and reinforced (pounded in) at the earliest possible time in a diver's career. It needs to be instinctual, habitual and a precondition to certification.
Loading on more gear as a substitute for this skill creates more problems than it solves and still doesn't solve the root problem.
If this poor fellow died because he burned his tank by mistake, either he wasn't trained properly or he forgot his training (I recall there was no suggestion of equipment failure). The better trained someone is, the more likely he is to remember his training when he needs it. I would suggest that, if anything be manditory, it be proper training and not more equipment, Halcyon or otherwise :-).
I hope this doesn't spin into something on ponies in general. That's a seperate topic. This thread is about gas management, not equipment failures.
PS One reason I was so hostile to your idea (as opposed to you, personally) is that I saw a parallel to the thinking that leads training agencies to take people to 130 fsw on their tenth dive and then award that idiocy with an AOW card. People aren't ready to go that deep right after certification just as people who can't manage their gas supply aren't ready for certification, but it happens everyday. No equipment makes up for that.
I look forward to your response.