Emergency ascents

[Charlie99]

What's the difference between exhaling all the way up and simply keeping your airways open? How can you tell if your airways are open or not?

Try this exercise:

Cough a few times. Do you notice how something closes at the back of your throat just before you cough? Now stay in the condition you are just before coughing, and try to inhale/exhale. Your airway is completely closed and air can't come in or out. DON'T STAY IN THAT CLOSED AIRWAY CONDITION UNDERWATER!

Now that you know what muscle are involved, you should probably be able to control it voluntarily (some languages uses that part of the throat to form a "glottal stop", and in some regions of US, it is used for the middle consonant of "bottle".)

Another simple exercise to get a better feeling for airway closure is to gently push on your abdomen. If your airway is open, air will come out. Close your airway and push again and no air will escape.

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Outside of ESA there is a very important reason to understand, be able to feel, and be able to control airway closure. If I want to ascend a couple of feet, an easy way to do that is to suck in a big breathe of air and let the extra buoyancy take me up a few feet. To do this, I pause my breathing while fully inhaled. It is important to do this pause by using the chest and diaphram muscles rather than by closing your airway at the back of the throat.

 

[DA Aquamaster]

Two thoughts that have not really been covered yet, at least directly.

You do not want to blow bubbles but rather keep the airway open because, if you are doing a long ESA and are blowing you are likely going to blow too much and run out of air on the way up. That won't happen if you open the airway and let the excess air vent naturally.

Keeping the reg in the mouth is important due to the possibility of getting another breath or two out of the tank on the way up. But more importantly, it is critical as the effort of inhalation (whether you get any air or not) will help open up and access areas of the lungs where air may be trapped (particuarly if you exhaled rather than opened the airway) and can prevent a lung injury.

And a couple more thoughts:

Practicing an ESA horizontally may make the PADI lawyers happy as it reduces their liability as the chance of a lung injury is reduced as there is no air expansion. But it is a totally ineffective technique and is unrealistic as there is no air expansion and it tends to encourage people to develop the habit of exhaling rather than keeping the airway open.

Following your bubbles up is not a bad way to go. But you have to remember to follow your smallest bubbles up and then constantly keep changing to the smallest bubble you can find. The tiny bubbles will ascend at about 60 ft per second, the larger ones will go up a lot faster.

 

[Vengro]

some languages uses that part of the throat to form a "glottal stop",

(My name has that kind of hacking, hairball sound in it. It can sound really bad if you don't know how to pronounce it correctly.)

I understand the problem a lot better now, so thanks for being patient and explaining it in more detail. You follow the smallest bubbles up and you don't force the air out, but let it flow out slowly so that you don't run into the situation where you force all the air out of your lungs, which leads to holding your breath, since there is nothing left.

When we were learning the emergency ascent, that was the problem I kept running into: running out of breath before reaching the surface. At any rate, I'll definitly be keeping a close eye on my SPG.

 

[wpscortland]

This is why they call you the voice of reason!