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

[Schwob]

Breathe out gently and stop the flow without closing your mouth

Thanks.
Got it, I think.
So I do exhale & appruptly stop with mouth open and that act closes the glottis. If I keep pushing to exhale (from where, not sure lungs I guess, but maybe akso chest and ir stomach muscles) despite the closed glottis I cannot and the upper airway area sort of has a congested, blockage feeling...
... and in that sense the light cough also now makes sense... the glottis as a studdering valve of sorts while forcefully exhaling = cough...

 

[The Chairman]

the glottis as a studdering valve

That is it!

The lungs have no muscles or nerves. The lungs lie in the pleural cavity and respond to the contraction and expansion of your chest and thoracic diaphragm. The exhale by contracting your chest muscles and thoracic diaphragm. You inhale by relaxing and then stretching those muscles the other way. The glottis is a two valve and is strong enough to cause damage to your lungs if the internal pressure becomes too high.

 

[Saltyhawg]

Agree with The Chairman that air management/monitoring is where the emphasis should be. How often would there be an emergency that is not related to being out of air occur? I.E. both regulators fail in a closed position? That would seem to be impossibly unlikely.

What else would require CESA?

 

[boulderjohn]

My OW instructor held her hand on our regulator to feel the air coming out on our CESA from 40 feet. That was a little weird.

This practice is extremely common--I do it. It is not just to feel air coming out; for me the main reason is that on occasion some students feel the need to spit out the regulator. With my hand there, that regulator will be back in the mouth before it gets all the way out.

We did it from ~ 20', but after my practice session on the way over, I could of easily done it from 40'+. I'm not saying that to blow smoke, I just mean that I see that it's possible to make noise, keep the glottis open while not expelling to much air, and all while making a safe ascent.

The difference between the horizontal CESA in the pool and the vertical CESA is enormous. With the horizontal CESA, the air in your lungs is not expanding; with the vertical CESA in open water it is.

 

[Todd Bissonette]

I was just reminded yesterday that the #1 Rule of diving is...

TO HAVE FUN!

My 2¢...

 

[rob.mwpropane]

I was just reminded yesterday that the #1 Rule of diving is...

TO HAVE FUN!

My 2¢...

I agree. For my first dives being in a cold murky quarry, I had a blast! All I keep daydreaming about is getting back under....

 

[MikkelBC]

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 get that there's people that just want to learn something, be able to say they can do it, get the certification and move on (there's nothing wrong with that). I've never been one of those people. I like to know something, not just learn it.

I fully support your eagerness to learn about the theory behind the best practices that are taught in your course. The reason the courses mostly don't go into too much detail is that for many students it tends to be confusing and counterproductive when all they need to learn to be safe at that level are some rather simple rules and principles.

You should also realize that there is a big difference between "knowing" something in theory and being able to execute accordingly in a stressful situation underwater. Practical training is what makes you able to act correctly in a stressful situation. The procedures you are taught are designed (based on many years of collective experience) to be as easy as possible to learn, remember, and execute correctly even in a stressful situation.

 

[rob.mwpropane]

I fully support your eagerness to learn about the theory behind the best practices that are taught in your course. The reason the courses mostly don't go into too much detail is that for many students it tends to be confusing and counterproductive when all they need to learn to be safe at that level are some rather simple rules and principles.

I agree why they don't go into detail in class, which is why I kept in depth questions to a minimum and came here. I was just there to learn the basics.

You should also realize that there is a big difference between "knowing" something in theory and being able to execute accordingly in a stressful situation underwater. Practical training is what makes you able to act correctly in a stressful situation. The procedures you are taught are designed (based on many years of collective experience) to be as easy as possible to learn, remember, and execute correctly even in a stressful situation.

Does that statement need to be made? No need to patronize, I get it, I'm green. Maybe I should have a signature that says "I'm new, I don't know much, just here trying to learn so I can go practice, practice, practice in the real world". That way it's attached to every post I make. I literally wrote this in this very same thread;

Ultimately, it's my decision and my responsibility (as well as those reading this behind us) to further my / their education taking classes, reading books, technical training, etc. This type of "conversation" is just the start,...not the end.

No one should come onto an internet forum, read a few passages as gospel, and then think it's ok to make life threatening decisions based on them. No one....

I'm not trying to be ignorant, so please don't take it that way. Your just stating the obvious, that's already been stated...

 

[TMHeimer]

This practice is extremely common--I do it. It is not just to feel air coming out; for me the main reason is that on occasion some students feel the need to spit out the regulator. With my hand there, that regulator will be back in the mouth before it gets all the way out.

The difference between the horizontal CESA in the pool and the vertical CESA is enormous. With the horizontal CESA, the air in your lungs is not expanding; with the vertical CESA in open water it is.

Of course I am aware of that. It's been a while since I've done it horizontally in the pool, but I'm not sure I really notice the expansion in my lungs CESAing from 20-30'.
Question: If you are doing a CESA from say 60', does the expanding lung air do anything good for you--ei. getting more 02 to your tissues? My guess would be no, since when the air expands is also becomes "thinner". Perhaps just

This practice is extremely common--I do it. It is not just to feel air coming out; for me the main reason is that on occasion some students feel the need to spit out the regulator. With my hand there, that regulator will be back in the mouth before it gets all the way out.

The difference between the horizontal CESA in the pool and the vertical CESA is enormous. With the horizontal CESA, the air in your lungs is not expanding; with the vertical CESA in open water it is.

Something happened when I hit reply. My post starts above "question". To finish, I suggested that the feeling of always full lungs is just better psychologically?

 

[BRT]

Of course I am aware of that. It's been a while since I've done it horizontally in the pool, but I'm not sure I really notice the expansion in my lungs CESAing from 20-30'.
Question: If you are doing a CESA from say 60', does the expanding lung air do anything good for you--ei. getting more 02 to your tissues? My guess would be no, since when the air expands is also becomes "thinner". Perhaps just



Something happened when I hit reply. My post starts above "question". To finish, I suggested that the feeling of always full lungs is just better psychologically?

That is a good question!