... Obviously, the rebreather world needs SOMETHING that enhances self-discipline in the divers.
And there are a few of us... actually a growing number... who have taken it upon themselves to spread the word.
Regarding CCR design and the human/machine interface... and I know you do not dive CCR so perhaps some of this will sound sketchy.
Michael and I both choose to dive an AP Evolution+ CCR. The design is truly remarkable. Not idiot-proof by any means, but extraordinarily robust with several layers of redundancy to keep the diver safe, including two controllers, two energy sources with smart switching between them, a heads-up display, a temp stick, three oxygen cells and a soon-to-be-released carbon dioxide sensor. Truth is that CCRs in themselves are not terribly complex. The basic design pre-dates OC scuba, and over several iterations, that design has been refined slightly, but essentially it remains unchanged and someone from the early 20th century trained on a rebreather would recognize the basic components. However, what has changed dramatically are the mechanisms that control the quality, quantity and suitability of the component gases within the diver's breathing loop. As these things become safer, they become more complex.
One important reason for diving the unit I dive is that AP developed its own electronics package. The Vision (that package) is a remarkable piece of work. It is complex... but the user does not have to know much more than which buttons turn it on and which turns it off. (A terrible over-simplification but bear with me.) I could teach someone the basics of diving a Vision controlled, Ambient Pressure Diving designed CCR in less than an hour... and have done so for Silent Days try-dives. The unit will keep the diver happy without much assistance. The remainder of a seven-day air-diluent beginner's course (yep seven days) is spent going over the OTHER stuff... options should something go wrong, testing the unit BEFORE diving it, writing out a personal checklist for assembly and pre-dive, etc. etc.
The issue is that the unit is easy to dive... several of the top machines are. They are so easy to dive that after 20 or 30 or 40 hours of trouble-free use, people become complacent. The checklist goes, their complacency builds, checks and balances decay: Risk increases by orders of magnitude. Manufacturers can and do try to make things easier for the end-user but this simply exacerbates the problem that there will always be an element, a personality type for whom a CCR is a time-bomb. I have friends who should NOT be diving a CCR. One of them does and one day he may kill himself. I have resigned myself to that understanding.
Folks like M2 and I can write articles and books, and those of us who are lucky enough to teach can influence the few instructors and divers we train, but that's really not enough. RESA was formed specifically to improve design, training and general knowledge about rebreathers. I support the concept wholeheartedly. I think we all should. And that's about the best we can hope for.
