Quote: (Originally Posted by
depth)
Ok, I see the points above. But I have never heard of a Rebreather diver actully identifying O2 or CO2 problems and succesfully switching to OC on a normal 2. stage or a BOW and recover! (but maybe i'm just not searching hard enough ;-) I found articles that describes how the RB diver senses that something is wrong, and the next thing he/she wakes up in a hospital thanks to the buddy.
I've seen my PPO2 not responding correctly and bailed ot OC to be on the safe side (O2 valve not fully open, opened and returned to CC) I've been breathing hard and thought I might be overbreathing (unable to slow rate after fast descent to 50mtrs) so bailed and caught my breath, eventually!
I also dived with the OPV set open instead of closed and was firing the ADV on every breath, very disconcerting, bailed out and surfaced, thats the only time I've canned a dive on the rebreather but not as potentially dangerous as the first two.
One of my buddies O2 started to overflow, he bailed then isolated the O2 and returned the the loop diving with the O2 valve on/off technique.
Maybe its easy to spot on the KISS as we're glued to our PPO2 displays?
I know those aren't very exciting examples but in each case an O2 or CO2 problem was detected and bailing out either allowed time to fix it or surface.
However you are right in that I too have heard of several instances where divers have gone from seemingly ok to unconsious very rapidly, the only way around that I can see is an Automatic BOV based on CO2 detection... or a full face mask/gag, otherwise your sucking sea, which is abit grim
I guess the rest of us are getting by with good packing, observing the scrubber time limits and avoiding too much work (never a bad thing
)
BEN