I understand that under no circumstances should anyone hold their breath while ascending however it seems that there are a few posts floating around that suggest that for whatever reason this still happens. I'm not trying to blame or shake my head at these people rather my intent is to further understand what happens.
When I try to to simulate a breath hold on ascent while on dry land (by breathing in as deep as I can) I can feel my lungs expand and my chest area feels tight. I'm not about to try this under water so I was wondering if anybody knew if you would feel the same sensation if this ever happened while diving. I can only imagine that you would feel pain as your lungs over expand. Anybody have any insight on this matter? Experience or hear-say?
These are the things that keep me awake at night...
I can remember two times when I held my breath on ascent. Once was a scary rescue (I had donated my reg and literallly forgot to put another reg in my mouth while I shot for the surface with a victim, so I "naturally held my breath") and another time I was being an idiot and jumping off the bottom in 12 feet or so.
For me, both times, I began to feel discomfort and an overfilling of the lungs and at the time I had my throat locked down and I was holding my breath. I quickly let the air out and maybe had some residual discomfort and a little cough, but no other symptoms.
In general, if you are calm, ascending at a normal slow rate and you do NOT have your throat locked down (i.e., you have the air way open or relaxed) expanding air in the lungs will naturally just come out by itself I would definitey NOT recommend anyone deliberately trying to prove or disprove this idea.
I think this question come up with new divers: What if I forget to exhale? The answer for 99.99% of people is that the air should naturally come out, if you are healthy, have no obstruction, and the ascent rate is reasonable.
Basically, as long as you are calm and actively breathing there should be no problem.