CT-Rich
Contributor
I think if you look at the complexity of the CCR gear,and the ability to die without prior warning and the deterioration of situational awareness as a diver approaches the point of death makes CCRs realatively dangerous. When a diver starts to become narc'd he will often be able to tell that he is not completely with it. Through training he will know that his ability to perform certain functions at depth are going to degrade and he has to plan his dive accordingly and train for those situations.
On the other hand ox-tox does not give warning signals for impending death. Judgement dregrades and the suffer is completely unaware that things are going badly south. It does not matter if you are diving to 300 fsw on OC or CCR those are highly advanced dives that carry significant risk of death. The point of my earlier statements were that you really need to understand the physiology and effects of gas at those depths.
As far as maintaining gear, I am sure that you spend much more time on your CCR than I do on my OC. OC regulators are almost idiot proof with proper maintainance. What ever comes out of the bottle I have a pretty good idea that it is breathable.... (unless it is a multi-bottle mixed gas dive.) A CCR is mixing the gas at depth, under user or computer control. If the user is not getting sufficient oxygen, he may well not be capable of even knowing he is in trouble or caring. By the way this was an excellent video 616fun, hypoxia - YouTube .
Am I saying that CCR are less safe than an OC? No, for most beyond 100 fsw dives I would think they improve the safety of the diver, especially in in cave, wreck or deco situations. Of course in those situations advanced training preparation is needed no matter what system is used. Like I said in my earlier posts, I am not trained in this gear and haven't been below 100 fsw for a long time. I never said I was an expert, but this thread was not originally about the safety of CCR, it was about the use of O2 beyond 40% and the safety of pushing the limits on ox-tox beyond 1.6. So saying that the internet "experts" should be quiet, doesn't really apply here.
While I am not an expert on CCR I have seen numbers that indicate that CCR does have a disproportionate hand in diving fatalities, on the order of 5 to 10 times the number of deaths per 100,000 more than OC Scuba..... Rebreather diving: ?Killing Them Softly? | Diver Magazine
On the other hand ox-tox does not give warning signals for impending death. Judgement dregrades and the suffer is completely unaware that things are going badly south. It does not matter if you are diving to 300 fsw on OC or CCR those are highly advanced dives that carry significant risk of death. The point of my earlier statements were that you really need to understand the physiology and effects of gas at those depths.
As far as maintaining gear, I am sure that you spend much more time on your CCR than I do on my OC. OC regulators are almost idiot proof with proper maintainance. What ever comes out of the bottle I have a pretty good idea that it is breathable.... (unless it is a multi-bottle mixed gas dive.) A CCR is mixing the gas at depth, under user or computer control. If the user is not getting sufficient oxygen, he may well not be capable of even knowing he is in trouble or caring. By the way this was an excellent video 616fun, hypoxia - YouTube .
Am I saying that CCR are less safe than an OC? No, for most beyond 100 fsw dives I would think they improve the safety of the diver, especially in in cave, wreck or deco situations. Of course in those situations advanced training preparation is needed no matter what system is used. Like I said in my earlier posts, I am not trained in this gear and haven't been below 100 fsw for a long time. I never said I was an expert, but this thread was not originally about the safety of CCR, it was about the use of O2 beyond 40% and the safety of pushing the limits on ox-tox beyond 1.6. So saying that the internet "experts" should be quiet, doesn't really apply here.
While I am not an expert on CCR I have seen numbers that indicate that CCR does have a disproportionate hand in diving fatalities, on the order of 5 to 10 times the number of deaths per 100,000 more than OC Scuba..... Rebreather diving: ?Killing Them Softly? | Diver Magazine