Quote:
| Originally Posted by scuba steve irl 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 |
Steve, I am on your side with your original OP but that above is a load of ar5e. The stimulation to breath is effected when hyperventilation is practised beforehand. After a normal breath, that stimulation will occure at the same rate as O2 is consumed and you'll hit surface gagging for breath. Black-out is caused by the
PO2 falling through your boots because CO2 has been flushed before breathhold through hyperventilation.
Berko
