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

[The Chairman]

Jennifer Alba saves two stuck divers by inhaling from a tank, swimming over to each, and giving them a breath mouth-to-mouth.

First, her name is Jessica.
Second, I think I need to learn this from her. Only from her.
Third, PLEASE, PLEASE, PLEASE, no one try this for real. It was a movie stunt. A lot can and will go wrong and they have safety divers all around to mitigate that. The worst scene in that movie was the guy who breathed straight off of a tank without a regulator. That ruined the whole film for me. Except for Jessica. Still, just because you see something in a movie doesn't mean it's accepted practice or has any merit at all.

 

[northernone]

I suppose a more accurate way to put it would be "If you hold your breath while ascending, your lungs will rupture, so you will suffer and/or die", but I wonder if there might be any reason they don't...

That's how I was taught. Memorable training style for an eight year old.

...Not a tone I emulate when instructing but I do mix in a fair amount real life stories of potential consequences for behavior. I owe it to those learning to have a clear understanding of the risks involved and the specific value of the behaviours and ideologies learned.

In my second DSD class during my mentorship I mentioned the 'rule' and said something along the lines of lung over expansion injuries can hurt so this is how we avoid them. The doctor who was attending the DSD class stopped me, took me aside, and requested I don't gloss over the rest of the medical risks involved like I did pulmonary barotrauma because he wanted to know the actual risks. Just because he was on vacation didn't mean he needed talked down too like a toddler. This rather curt rebuke stuck with me.

Regards,
Cameron

 

[The Chairman]

This rather curt rebuke stuck with me.

It's why I teach the acronym: Breathe Or Your Lungs Explode, Stupid! It's yet another reason why I make them master buoyancy control in OW. A diver should always be in control.

 

[Saltyhawg]

Hey there is one way you can expel air with a closed glottis! Tracheoesophageal fistula....course I hope no one has that.

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. I agree that making sounds as you ascend is expelling too much air.

The only time I hold my breath (with an open glottis) is when I'm using my lung volume to control buoyancy for a second to take a picture, rise a little to get over a coral when drift diving, etc.

 

[TMHeimer]

Hey there is one way you can expel air with a closed glottis! Tracheoesophageal fistula....course I hope no one has that.

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. I agree that making sounds as you ascend is expelling too much air.

The only time I hold my breath (with an open glottis) is when I'm using my lung volume to control buoyancy for a second to take a picture, rise a little to get over a coral when drift diving, etc.

Any time CESA comes up I mention that when I practice it I start out with half full lungs, not "take a good deep breath" as instructors tend to tell students. I figure if I had enough air to get a full breath then I'd be at least starting out making a "normal ascent". Starting with lungs half full means a real slow exhale, sound or not (for me anyway).

 

[rob.mwpropane]

Well, we did it as our last skill on Saturday. The whole way there (about an hour) I practiced making different "aaahhhhh" noises, because I knew it would be required .(The whole time I was imagining if someone had to ride with me or if there was one of those hidden cameras in the vent how funny it would of been!)

I finally found a deeper "aaahh" that allowed me to make noise, while not expelling too much air. I think in the beginning when I first learned of the skill I did an "aaahhh" like in the doctors office, but for me that expelled way to much air. I kept imagining blowing on a fire to get it lit (direct and slow, but steady), made the "aaahhhh" sound to go along with it, then incorporated the size of the regulator in my mouth.....again, probably a really funny sight.

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.

 

[Blasto]

You're supposed to be able to do it from 40m.
40' is a good first-time depth for freediving - ventilate, go to 40', go up, until you're comfortable doing it slowly.

 

[The Chairman]

Another handful of reasons I'm glad my agency (NASE) doesn't require the CESA.

• It's the wrong way to handle an OOA
  • Where's your buddy management?
    • What do you mean you lost your buddy?
    • That ends the dive right there!
  • Where's your gas management?
    • There's just no excuse to run out of air
    • None!
• It's impossible to repeat this skill until it is truly mastered
  • 10+ times minimum
• Swimming to the surface is pretty instinctive as it is.
• CESAs cause injuries to students
• CESAs cause injuries to instructors
  • Most likely cause why instructors get bent way more often than divers
  • Most likely the leading cause of instructor burn out!
• CESAs set a horrible example for students!
  • Every dive should consist of one descent, a safety stop and an ascent
  • Every student wants to mimic their instructor.
    • If the instructor does a bounce dive then so can they
  • Too much emphasis on the last ditch solution.

 

[Schwob]

I seem to be glotissionally unaware or challenged.

I get the whole CESA thing and the sound thing and that the glottis must be open while a sound is produced to allow air over the vocal cords.

I also think I generally have my glottis open when diving, but reading all this, I wonder how to tell for sure if I really have it open while not expelling air (taking pics etc).

Or, reversely, how to tell when it is closed. When in normal life is the glottis closed?What do you do that forcibly must cause the glottis to be closed? (Sorry I am lost about producing cockney sounds and trying to sound "Uh-Oh" and "warching" for the glottis to clise seems to not aid my glotissional awareness at all )

I am asking to realize for myself "oh, now the glottis is closed and that's how it feels like for me"...
I am realising the fallacy in and risk in asking anything about a "feeling" on the internet. Apologies in advance.

 

[The Chairman]

When in normal life is the glottis closed?

The glottis is open by default. Do a small cough. Make it light and feel where it comes from. Now experiment some more with sounds like a soft "uh". Breathe out gently and stop the flow without closing your mouth.