I am done with the pool and classroom work.
I know not to hold my breath but in general I mean it's hard for me to "not inhale" for 30 seconds, whether I'm holding it or blowing bubbles. I feel I run out of air faster when I let a little air out of my mouth so maybe I need to work on that too.
And yes as someone mentioned, you do it in the OW but you have your regulator in so there's no chance or not making it.
I was also told that in the OW checkout dives for this skill, they expect you to make some kind of high pitched noise so they can hear that you aren't taking any air in and cheating. I tried that last night and it was very awkward and I was having trouble making a constant noise out of my mouth while simulating it.
Then on my drive home from work now I was trying it in my car and then realized how easy it is to make that high pitched noise when I have my mouth shut and am blowing the air out of my nose. I also find that easier to move air slower out of my nose in that fashion than out of my mouth. So perhaps I can just do that while I am doing the CESA skill? I made it like 40 seconds while testing this out in my car but again, I was just sitting down driving lol.
Oh and one more thing. I had seen videos of the free flow skill and I simply did not understand it. I didn't even really understand it when my instructor told me about it and was explaining it to me. But when I actually did it, wow, that is really weird lol.