Quote:
| Originally Posted by A. Berk 200% wrong Steve, shallow water b/out is caused by reduced PO2 which cannot sustain consciousness and also a reduced PCO2 which does not kick-in the urge to breath strongly enough before you pass-out 
roBek  |
the urge to breath is caused by the ppco2 build up . when on a snorkel dive the urge to breath is not stimulated for slightly longer . it is when the ppco2 rises to a certain level . the ppco2 is greater than the ppo2 and the body switches into a blackout stage
the increased ppco2 is not a bad thing at small levels ...
IMO the body needs to feel the slight elevation and this feeling so that we can react calmly .
anyway we have moved anyway from what the thread was meant for