Greetings padiscubapro,padiscubapro:There have been multiple deaths on scrs and more than one close call by divers that have gone hypoxic.. There are probably many more SCR deaths tha CCR deaths.
Its VERY easy to overbreath an SCR.. ...The KISS is very difficult to overbreath
Sorry, I didn't explain myself clearly (not the first time). What I mean "overbreathe" is kill the scrubber, not decrease O2 content by metabolising down to hypoxic level. This was my concern about Sport KISS. The scrubber is uninsulated, convoluted and gas path is long. The risk of scrubber breakthrough in cold water under heavy exercise is significant, in my view. And, it is a higher risk in a CCR than SCR because CCR scrubber has to "work harder" as all gas is recirculated. There is little you can do when you break through the scrubber. I managed to kill a scrubber once in cold water during heavy exercise. You can flush as much as you want, but the problem comes back almost immediately. You have to bail out.
What you mentioned I call a bad technique and should never be a problem in any well calibrated and operated SCR or CCR. In a SCR, during increased exertion rate (and specially close to surface) you simply press bypass from time to time. Specially so if running on low content mix, like 32%. I have never done any agency's SCR training (even though somehow I am factory qualified to train people on some SCRs :death2: ), but I would imagine that this is normally explained during the first lesson.
Cheers,
Pawel