Yes, I’d forgotten the leaky O2 valves, does make things a tad simpler!
I don’t have a lot of experience on different CCR, so take my comments for what they are worth, but I do think that the level of automation that current eCCRs have is fine for a thinking diver and the “yellow box of death” status is probably overdone. I don’t believe that your CCR is actively trying to kill you (although that’s perhaps not a bad mentality to have, keeps you on your toes). The information is there to keep a breathable loop, it’s the (mis)interpretation that tends to lead to incidents. There are drills and techniques for pretty much all events (one cell voted out? dil flush to a known gas. Breathing rate going up? Bailout to known gas, etc) but we don’t always take the right one. But that has to be addressed on the training side, not so much on the equipment in my view, similar to technical OC diving. A computer is very good at doing repetitive tasks over and over, something that a human usually isn’t. Current eCCRs are reliable, they can keep setpoint if you ask them to and to report ppO2, leaving the diver to monitor, think about and act on the information provided.
Where I will concede there is a difference between OC and CCR, and hence on the safety of ccr, is that there are perhaps fewer “allowable” mistakes that you can make before you are so deep in the incident pit that recovery is impossible. Which is why I don’t believe in “recreational” ccr, although I will readily admit that I have not tried units such as the Hollis Explorer or Poseidon Se7en. To me, you need to have a more “tec” minded attitude to dive a CCR, be aware of the nature of the system you are using and work with it, not just throw something on your back and jump in. I think more automation / safety checks etc is actually not the way to go, it fosters too much dependence on everything working just so, which in a low volume market will never find the cash to fund the development required. A resort diver can grab a tank and go diving. If that particular tank setup doesn’t “work” (its empty, the BCD leaks, whatever), chances are he can grab the next one in the rack and not miss the dive. I don’t see there ever being enough volume CCR units for that to happen, and so with all the time pressures we have in life, corners will be cut and bodges made to get the unit in the water somehow.
So, in a very long winded way (sorry), I think CCRs are safer if you look at them with the same mindset as you would a tec diving rig. You need good training to handle stages / different gasses, and similar to handle a CCR. If you have that training they are great to dive IMHO and are nothing to be scared about. They don’t need to be the preserve of hard-core technical diving. I don’t think they are safe enough for “casual” rec diving however, and nor will they be any time soon.
-Mark
