Need a knowledgeable freediving instructor to address this.
I've only experienced them a very few times, always when pushing into substantially deeper water than I was acquainted with. I'm reasonably sure depth of onset will depend on the diver, but normally somewhere approaching RV. Its my understanding that they are triggered by chest compression greater than the diver is used to. For me, they feel like a sudden, huge contraction; a massive chest heave that comes completely unexpected. C02 contractions come on much slower and are normally mild at first. The first time for me was so surprising, I did not notice where I was vis a vis urge to breathe. The second time, it was before I should have had much urge to breathe. Finally, once I knew what they were, I could control them (and come up quick)
All this is just me, others may differ.
Connor
I've only experienced them a very few times, always when pushing into substantially deeper water than I was acquainted with. I'm reasonably sure depth of onset will depend on the diver, but normally somewhere approaching RV. Its my understanding that they are triggered by chest compression greater than the diver is used to. For me, they feel like a sudden, huge contraction; a massive chest heave that comes completely unexpected. C02 contractions come on much slower and are normally mild at first. The first time for me was so surprising, I did not notice where I was vis a vis urge to breathe. The second time, it was before I should have had much urge to breathe. Finally, once I knew what they were, I could control them (and come up quick)
All this is just me, others may differ.
Connor
