Quote: (Originally Posted by
Steve)
Well, for what it is worth Mike the way a CO2 issue whilst diving makes me feel is very different to the way an experiment like yours makes me feel. Anecdotal I know but I'm no medical researcher.
PS. Buy a OC/CC DSV
I figure it must be... I'd like to understand why though.
There is definately the issue of a closed system with the rebreather vs the open system when exercising, but I'm surprised it's that great.
I figure there are three scenarios diving;
1: the 'upside down scrubber', where there is no scrubbing at all
2: the 'I forgot the bucket O-ring' where there is reduced scrubbing capacity
3: the 'do I feel lucky' (I know what your thinking, did I put 5 hours on this scrubber or six? Well, to tell you the truth, in all this excitement I kind of lost track myself. You've got to ask yourself a question: Do I feel lucky? Well, do ya, punk? ) where there is reduced scrubber capacity but still some remaining.
The first one should get picked up in the boat on prebreathe (on the basis that we have a loop volume of say 15 litres and are producing a minimum of .5 of a litre of CO2 a minute, therefore we will hit 5% co2 in 90 seconds)
Both 2 and 3 should be analogous to any anerobic exercise - you are getting rid of some, but not all, the CO2 each breath. Therefore CO2 will build up to uncomfortable levels over time - but it should take a minimum of 90 seconds to get to the dehibilitating stage, and that should be long enough to recognise and react?
Mike