Andy -- question -- is it the practice of "air sharing" to extend BT itself you believe is wrong or the practice of "air sharing" to extend BT and being a role model for those who don't have the skills that is wrong? That is, IF it were just the two of us, or the two of us and a guide, would it still be a "bad practice?"
I'll admit there are other solutions I'd rather do -- for example, start the dive with more gas (an AL 100 vs. an 80 for example) OR do the dive with a stage and keep the back gas as my reserve. BUT, taking the stage issue for example, would THAT be setting a bad example in your eyes? After all, the typical vacation diver doesn't know how to dive with a stage either -- but if I was doing so, would that be wrong? Must we all be constrained by the lowest common denominator in group/vacation diving?
In a nutshell;
1. Not immediately aborting a dive, when one or more divers is low-on-air is wrong. I think that's black and white.
2. Extending bottom time through pre-meditated air-sharing isn't "wrong" from a safety perspective (assuming competence and confidence on behalf of the divers), but it does IMHO count as an 'improvised' technique.... where other formal techniques already exist.
3. A formal technique should always be preferable to an improvised technique - in this case; the pre-planning of diver's air requirements versus the dive they intend to complete and subsequent equipment with adequately sized cylinders OR, alternatively, planning a dive based upon sound knowledge of the diver's air consumption versus the supply they have available.
4. Air-sharing to extend bottom time is contrary to the principle of K.I.S.S. and opens up a number of variables that could negatively influence an accident chain.
5. Air-sharing to extend bottom time requires skills beyond those trained to divers at a recreational diving level - thus safety becomes reliant on the individual diver's experience and competence. Those skills are not 'advanced' - they are a mis-use of a basic technique designed, taught and promoted for another purpose (emergency ascent).
6. If this technique could be formally trained - try writing a distinctive specialty that encompasses it.... and see what the agency response would be.
7. It could be argued that pre-planning air shares to extend bottom time detracts from self-sufficiency. The diver enters the water without the ability to complete the planned dive without the assistance of their buddy.
8. If the technique can't be recommended to other divers universally, then there must be issues. Whenever experienced divers/pros find themselves in a "
do as I say, not as I do" situation, it ultimately points towards a practice that cannot be defended. You give the example of "using stages" - that IS something that can be recommended to novice divers - with appropriate training. i.e. "
Do a tech basics course first and learn how to use the kit" There is no appropriate training for air-sharing to extend bottom time... there is no appropriate training to recommend.
9. If a tree falls in a forest - does it make a sound? If a technique is practiced out-of-view of other divers - is it correct?
10. If you felt the need to 'hide' this technique from novice divers, because you feared they would replicate it - and otherwise couldn't justify the technique on account of progressive training you had received (
"I learned to do this on the X diver course... you should do that course before you attempt this technique yourself") then perhaps there is some element of denial about its legitimacy?
Having worked in the dive industry for a number of years, I've encountered more than a few gas guzzlers. I am a former gas guzzler myself, but experience now puts my air consumption into a very comfortable bracket and the issue has ceased for me. I do understand the frustration that a gas guzzler experiences though - it's depressing to be 'the one' that always causes a dive to end.
What I recommend to gas guzzlers is an appropriately sized cylinder. That removes the frustration - not only permitting sufficient bottom-time, but also removing the factor that quite often causes divers to feel ashamed or guilty. That, in turn, relaxes them and actually improves their air consumption. I don't believe that air-sharing offers the same benefits - because those divers are still a 'special case', requiring the assistance of others.
The solution I recommend now is using doubles. I use doubles for all my diving, except for teaching OW class. I used to use back-mounted indie doubles.... now I use sidemount. Air consumption is irrelevant because of that. When faced with a gas guzzling customer, I always offer to spend a couple of days with them to resolve the issue - I run 'intro to doubles', sidemount, tec basics and diving clinics etc that provide them with the tools they need to ultimately end their problem forever. It's a case of
not trying to make a square peg fit into a round hole.
It is likely that a gas guzzler may have difficulties sourcing rental cylinders of greater capacity. That's a problem that I wish the dive industry would address. However, there are options for using multiple cylinders - that do have a 'pedigree' in formal, consented, training.... at a recreational diving level.
Put a gas guzzler into doubles and sidemount... and just see how that transforms and improves their enjoyment of diving. In contrast, air-sharing to help them is just another facet that reinforces their low self-worth and reliance.
I
could just air-share with those people - but that'd be a short-cut which would ultimately do nothing more than deny them the opportunity to resolve the problem permanently. Air-sharing to extend bottom time addresses the symptoms, not the cause. Improved diving technique, plus access (via training) to appropriate gas supply is the 'proper' solution.
