Quote: (Originally Posted by
Steve)
If the number of posts on this site dedicated to the problems with the 2 most common onboard setpoint controllers that do deco calculations are anything to go by then I will continue to stay away from them. I take my diving and life more seriously than to use them.
If there is a difference between onbaord and offboard deco then there is a problem somewhere. It is as simple as that. It is most likely to be with the aforementioned bug riddled HH or Vision or poor diving practices. Why plan a SCR bailout around the most likely thing to stuff up on a rebreather?
It seems there is way to many people keen to buy more gear to make up for their lack of ability and shitty gear. It's a bitter pill but a good many people need to swallow it
Steve has said a mouthful, and I agree. Here comes my mouthful. Novice divers who are intimidated by the many responsibilities of CCR diving will find comfort in the idea of integrated deco with the promise of "It's all taken care of", not the kind of comfort I like when diving CCR.
The fact is that a CCR problem has never really been taken care of until you take care of it yourself. Constant PO2 diving is deceptively simple-as long as you can maintain a constant PO2, your dive plan is pretty simple. The problems start when you can't maintain a constant PO2, either due to equipment failure, or human failure-not paying attention, bad planning, not enough gas.
No matter which failure you have, decisions will have to be made, decisions which current integrated ECCR controllers are not sophisticated/thorough enough to make without human oversight. I want to be able to see my PO2 even with an electronics/main power failure. And I want to be able to disable the solenoid in a low power/emergency situation so I can keep the displays going and better manage my emergency-2 examples. Anyone can manage the PO2 well enough as long as they have a reliable display, I don't need any help beyond that. The best controller is one which controls the least, yet is able to maintain PO2 best-IMHO.
Help is the key word. Most CCR divers go on and on about complacency and it's insidious effects, but many still find integrated deco an attractive proposition. I'm not sure I understand this. The truth is that CCR diving always requires a high level of diver involvement in the system. The optimal level is debatable, but one thing is sure, you need maximum flexability to handle the many complexities of constant PO2 diving emergencies. I can think of no other land mammals able maintain constant PO2 through any means, mechanical or otherwise.
Oh and finally, there's the division of labor. It's plenty hard to design an ECCR that has a good scrubber, low WOB, maintains set point well and is reliable. Asking for an integrated deco function with all that is, IMHO, expecting a lot. I say let the CCR designers do their best and let the dive comp manufacurers do their best and let us divers do our best. It's not so reasuring, but it is realistic.