Those actively pursuing any form of underwater activities these days are at the very least acutely aware of rebreather technology. Its benefits are well proven and documented, training programs are well established, and the development/manufacturing community is ‘slowly’ making strides towards performance and quality assurance consensus standards.
The underlying problem is that this technology is incredibly unforgiving. The big three things to worry about – hypoxia, hyperoxia, and hypercapnea – are all largely dependent on the unit’s subsystems’ performance. Naturally, human factors have a way of interfering with system performance, and what it all boils down to is that the mindset in driving a rebreather is inherently different that diving more conventional open circuit scuba, and this bites people…hard.
My perspective is this…as soon as a rebreather is put on your back and you take that first breath on the ‘loop’, that unit is a part of you. You’ve taken your environmentally regulated ‘atmosphere’ that you were breathing while walking down the street, packaged it up, and put it on your back in a closed system, that YOU need to regulate with this technology. End users have to understand the concept of managing an ‘atmosphere’, THEIR atmosphere, to mitigate risks associated with the big three. This means gaining a thorough understanding of both mechanical outputs and inputs into the system, as well as monitoring the system. Your brain does this, not the unit.
Discussion could go on for days and for thousands of pages on the subject of rebreather design, operation, and safety. My take-home is this – all units themselves are a compromise of form vs. function. Use the unit for what it is…yes its a cool toy, but more importantly, it’s a tool that allows incredible range extensions for undersea exploration. Forget about this toy or that aftermarket part and whatnot…what really matters is the user’s ability to manage his/her atmosphere…comfortably, effectively, and CONFIDENTLY.
Be safe out there.