Hi Carl, Welcome on board!
Quote: (Originally Posted by carlthecat)
Recently, I watched 2 shows, one on Discovery
:-) Don't believe everything you watch on television! Quote: (Originally Posted by carlthecat)
1) Does/Can a rebreather give a diver 10-13 hours of breathing gas? If so, what is the maximum (ball park is ok)?
Er, yes and er... no. :-)
"Most" rebreathers on a single dive will last 3hours, a couple of extreme models 5-8 and few people have strapped two together to do longer.
The limiting factor is the CO2 scrubber which will last a limited amount of time depending on the amount of scrubbing material in the rebreather, the workrate and depth.
With full tanks the gas available is often enough for 10hours diving though.
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Quote: (Originally Posted by carlthecat[/COLOR)
]Is the amount of breathing gas variable with depth like OC systems?
Er, yes and er... no. :-)
The amount of gas is pretty constant, remember we're only replacing the Oxygen here the amount of which remains fairly constant irrespective of depth.
The amount of breathable gas is limited by the life of the scrubber, you'll still have gas left after several hours but chances are the CO2 scrubber will be exhausted is very high, some rebreather have ways of measureing this, everyone else just times there dives, done 3hours on the scrubber, yes- then chuck it away.
Quote: (Originally Posted by carlthecat)
Which rebreather models provide the highest breathing capacities?
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Don't quote me but I think, CCR- Oruoboros, CisLunar and Mk15series can go longest, SCR- RB80 and clones carry the most scrubber. Or just carry two or more rebreathers.
Quote: (Originally Posted by carlthecat[/COLOR)
]2) How can a CCR diver change from one diluent to another in the middle of a dive? All the CCR rigs I have seen have one bottle for O2 and the other for the diluent. Do they change the dilutent bottle under water or is a 3rd bottle added to the rig?
Why would you? Most of the time people use one diluent for the entire dive, even very deep dives as you use the onboard O2 supply to make the hypoix mix breathable in the shallows (not much good to bailout on though!)
If you needed too, on an extremely long dive for example, then a QR on switch block can be used.
Quote: (Originally Posted by carlthecat)
I will continue reading and learning about the interesting world of CCRs.
Well I think you've come to the right place, the people on here have given me alot of advice but remember, just like the TV- not everyone here knows everything, so until you hear otherwise assume everything I wrote could be wrong!
BEN