#1 Rule In Scuba, Don't Hold Your.....

[boulderjohn]

1. When doing the CESA for real, the air is expanding as you ascend, and you thus have plenty of air. It is not at all like doing it horizontally in a pool.

2. When doing a CESA for real you tank is not actually empty. It just thinks it's empty. Your regulator has to have enough pressure coming from the tank to deliver air to you at greater pressure than you are under at the moment, or you can't inhale. When you ascend, you will under lesser pressure, and you will get a breath if you really need it.

3. There is a difference between holding your breath and pausing your breathing. As you sit back, completely relaxed, pay attention to your breathing. There will be times that you are not inhaling or exhaling, yet you are not holding your breath. That is OK, because air that wants to escape from your lungs can do so. I pause of a few seconds after each inhale and each exhale.

 

[The Chairman]

Just keep your glottis open. I teach students to breathe, take a super breath and pause without occluding your glottis. It's easy enough to do and if you ascend with your glottis open, you will bubble naturally. A super breath is done using your chest muscles and pausing like that involves holding your chest muscles out, not in occluding your glottis.

During OW, I still want to see fine bubble when the reg is out of your mouth.

 

[rob.mwpropane]

I appreciate the responses, and I get why they say it for class. I wasn't interested in that, just the practicality of the "AHHHH" in the real world.

If I really think about it in a real situation I'd rather remove the reg from my mouth as to blow a slower, steadier stream of bubbles....kind of like blowing on a camp fire. I can do that for a lot longer than making noise.

I didn't know what it was called, but that's what I wanted to get to. The "glottis" (thanks chairman). As long as it's open, airway is open, no over expansion or lung issues.

Again, I'm not asking any of this for class. I think we'll ascend from what 20'-30' from a platform? I read that some other class had people doing it from 100', I just couldn't imagine saying "ahhhh" from 100' and not running out of air from expelling to fast. I can however see blowing enough to make sure the glottis is open, but not enough to expell everything, all the while letting the air expand.

I hope this all makes sense. I realize that the better approach is to watch my gauge, dive within my means, and don't get myself into something.....then I'll never have to do a CESA, but I still like understanding something better than PADI explained it in the book/class. (Yes, I asked questions in class and the final answer I got was......... "AHHHHHHH").

 

[The Chairman]

If I really think about it in a real situation I'd rather remove the reg from my mouth as to blow a slower, steadier stream of bubbles

No, you don't. As you ascend, air will become available from your tank. Every atmosphere you ascend (33 ft) will give you a breath or two. If you take your reg out, you then have to clear your reg. Leave the reg in so you can inhale every now and then and not worry about clearing it. IOW: Leave your regulator in your mouth!!!

BTW, Boyles Law can be remembered as an acronym: Breathe Or Your Lungs Explode Stupid!

 

[boulderjohn]

If I really think about it in a real situation I'd rather remove the reg from my mouth as to blow a slower, steadier stream of bubbles....kind of like blowing on a camp fire. I can do that for a lot longer than making noise.

You do NOT want to do this. While ascending straight up, blowing a slower, steadier stream of bubbles will not be an important issue. You just need to be blowing bubbles.

If for some reason you inhale upon ascent with your regulator out of your mouth, you will inhale water, and you will drown. That is not a good thing.

If, on the other hand, you leave the regulator in your mouth and inhale upon ascent, one of two things will happen:

1. Nothing
2. You inhale air, because you are now under lower pressure and the regulator can deliver it.

Neither of those scenarios is bad, and one of them is very good.

 

[rob.mwpropane]

No I understand about not taking the reg out, I just need to practice slower bubbles through the regulator.

 

[TMHeimer]

Great basic explanations from Pete & John. Details on being in control of your airway passages. Making a sound while exhaling means your airway is open, but it can be open without the sound. Your throat can be closed while you do make a sound if you figure out how (but air would still come out your nose causing a possible mask leak)--that, I guess is why "AH" is chosen, as you can't do this with closed Glottis. Having this knowledge and control, I suspect, is why some students breeze through mask skills and others struggle.
I know a fair bit about breath/airway control as a wind player, but am not an expert in physiology. So, I still "AH" to be absolutely sure.
You can pick up a lot of knowledge from other courses, but other than Rescue Course, you're pretty safe if you just do what you learned in OW.

 

[MargaritaMike]

No, you can't be 100% "sure." Even the most skilled diver might float up or down a little in midwater without a visual reference. I recall being taught to blow bubbles "ANY" time a reg is not in my mouth underwater. Like the rule to "NEVER" hold your breath, it now seems a little crude. Once a diver has gained enough experience to be able to maintain depth within a few feet while swapping regs or doing whatever, I think he can replace "any" and "never" with common sense.

I've only been diving for a little over 33 years. I think I have pretty good situational awareness. There are two things that I do every time I dive: 1) NEVER stop breathing and 2) ALWAYS exhale under water when my regulator is not in my mouth.
I learned this in my OW class and have practiced it since. My thinking is that if it ain't broke, don't fix it.

While taking my DM class the other 5 DMCs and I would go fun diving and bet the first round on who could make the deepest practice CESA. Always paired with a buddy with air available, we started pretty deep. We did this for FUN. We had to maintain proper ascent rates (no faster than the smallest bubble) and were always a target for disqualification from the contest by our peers. At one time or another we were all DQ'ed, but it was great fun.

Bottom line imho is don't break rule #1.

Cheers - M²

 

[rob.mwpropane]

Really appreciate everyone's experiences and explanations. This cleared up a lot of grey area for me. I will practice breathing slower out of my reg.

Really like the new word I learned "Glottis". Never heard it before, but it sounds like that makes all the difference in the world.

Here's something else; I've noticed a few comments in this thread that note that you can blow bubbles, or make noise with the Glottis closed. While I understand that this may be possible (I can't make noise, but I can blow bubbles with it closed and a mouth full of air), doesn't it take someone consciously wanting to do so in order to make that happen? I mean, how many people out there are going to make that much effort top keep it closed while doing the one thing in the world that it's MOST important to keep it open?

Are some of you guys/gals pointing that out just to be 100% factual? You don't expect someone to work that hard....at trying to hurt themselves do you? I'm just curious why it's been brought up a few times?

(P.S. - During my CESA, I'm going to be thinking "Glottis, glottis, glottis, glottis, glottis........")

 

[The Chairman]

I've noticed a few comments in this thread that note that you can blow bubbles, or make noise with the Glottis closed.

Absolutely NOT possible. Not remotely possible. You can't make noise with your vocal chords if air is not passing over and they comprise the seal of the glottis. You can clap or snap your fingers, but if you're humming, making an ahhhh or eeeeeee sound, then the glottis is open. It has to be.