padi ow, why is CESA recommended to 9m?

[Skittl1321]

If I had not been taught how to properly do a CESA I would have died on my 3rd open water checkout dive.


Made the swim up but dropped weight belt on the way.

That is terrifying! Thank god you made it. Is the instructor still teaching?

But, if you dropped your weights, isn't it no longer a CESA? (the "C" being controlled, and a weight drop making you positively bouyant and no longer being controlled?)

 

[videofly]

Having never suffered from air over expansion in the lungs during an ascent, I have several questions. First, if you are ascending using the CESA procedure and you ascend too quickly, will the expanding air in your lungs push its way out of your mouth at a higher rate than expected without injury? Second, when an air over expansion event is occuring or beginning to occur in the lungs from holding your breath during an ascent, would you feel excessive pain in the chest area, letting you know that you need to exhale?

 

[dumpsterDiver]

Having never suffered from air over expansion in the lungs during an ascent, I have several questions. First, if you are ascending using the CESA procedure and you ascend too quickly, will the expanding air in your lungs push its way out of your mouth at a higher rate than expected without injury? Second, when an air over expansion event is occuring or beginning to occur in the lungs from holding your breath during an ascent, would you feel excessive pain in the chest area, letting you know that you need to exhale?

If you are healthy and have the airway open, you can ascend at a super high rate without damaging your lungs. Not something you or I should test, but the excess air will just come out. i have forgotten to exhale in a dive emergency and felt an uncomfortable pressure and then released the air.

 

[t4e]

the book says if ooa, & your buddy is far, if you are less than 9m deep do cesa (controlled emergency swimming ascent) , but if you are deeper inflate your bcd to do an uncontrolled bouyant ascent

the latter sounds like a death sentence. why couldnt cesa be the method of choice for 18m depth? since you have some remnants of compressed air in your lungs you should (i guess) be able to swim that long minute to the surface?

anyone practise cesa in their training from these depths?

thx

how, if you're out of air?

 

[matt_w]

The best solution is simple. If I were to go out of air I will simply reach down near my hip on my Parkway BCD and inflate rapidly using the trusty built-in CO2 cartridge.....wait a minute....I thought this was 1984. Never mind. Carry on without me.

Having done this at about 18M, I can assure you it is very disappointing.

 

[beanojones]

Having done this at about 18M, I can assure you it is very disappointing.

What actually happens?

(The only time I tried to pop a CO2 cartidge underwater, it had actually corroded to the point it just sort of crumbled apart at the fitting Once I finally managed to pull the string hard enough.)

 

[Tortuga68]

What actually happens?

Not much. A CO2 cartridge contains about 1/4 litre of gas.

 

[Skittl1321]

how, if you're out of air?

The poster misread. It says to inflate your BCD on the surface. You'd do that using all the air that is now surrounding you once you reach the surface.

 

[Tortuga68]

As he corrected:

you guys are right, the book doesnt say inflate bcd during cesa, but inflate on the surface after cesa, my bad

And as other people noted, in addition to oral inflating (as taught) you'll probably be able to access some air from your tank due to the lower ambient pressure at the surface

 

[beanojones]

Not much. A CO2 cartridge contains about 1/4 litre of gas.

I was looking that up and the usual answer that came out was 7 litres.

If the CO2 cartridge was so tiny, it would not be being used for DSMBs.

Am I missing something?