Question about a situation

[master00sniper]

One that is entirely avoidable by having a redundant air source or a buddy, but I've often wondered about this anyways.

Your diving, and you have an OOA emergency at 50 feet. Whether solo or your buddy is too far, in this case your only option is to go up.

Where I dive, at 50 feet deep neutral buoyancy means quite a bit of air in my BC. I have a bunch of neoprene to weigh down to get me down. This means a lot of extra air expanding in my BC on my way up. Obviously you don't wanna go up too fast, but isn't it a shame to release air out of your BC when no air is the reason you are going up? Would it be unwise to just stick the inflator hose in your mouth and reverse the process of orally inflating your BC?

The only cons I could come up with didn't seem like reason enough to not try it in a real emergency, when it starts looking like you might not make it to the surface.

I would imagine the air quality isn't as good as it is coming out of your BC. You might get some water mixed in as well. It also wouldn't really slow you down if you needed too because the air isn't really escaping, just transferring over to your lungs. Are there other reasons not to attempt this in a real emergency?

 

[vjanelle]

Lung infections are pretty nasty. Learn what rock bottom/minimum gas is for team diving or bring a redundant supply for solo.

 

[porgyhunter]

I have also thought of the use of BC air in a life or death senario. I know the air going into the reg from the 1st stage is about 120psi I sure this is for a reason. The BC may be unbreathable because low psi

 

[GrumpyOldGuy]

If you did run OOA, as you ascend you are going to be able to get another breath or 2 of clean air form your tank as the ambient pressure decreases.

 

[ItsBruce]

If you are out of air, you should not delay a CESA to try to breath from your BCD. Just blow and go. And, my guess is that if it is so bad that the difference between life and death is breathing from your BCD, then, it probably isn't going to be enough to keep you alive.

BTW: If at 50 feet you need a lot of air in your BCD to be neutral, then you are probably overweighted. However, your wetsuit may also be too old and therefore is compressing too much.

 

[DevonDiver]

Unless you disinfected your BCD/Wing bladder daily, then this would pose a risk of lung infection. Someone once posted a report here on the board about the 'nasties' bacteria that grew inside a BCD bladder.

If your reaction to an OOA emergency at 50ft was correct, you'd make an immediate CESA to the surface. Less than 1 minute ascent to the surface is achievable by all divers. If not, then they shouldn't be diving... and shouldn't have been certified in the first place.

Given the expanding air in your lungs, and the possibility of more air becoming available via your regulator on ascent.... the standard CESA is the correct option. As taught, keep the regulator in place in your mouth. Look up. Kick up slowly. Maintain an 'aaahhh' sound until you break the surface. Orally inflate once there. There is no point in risking a life threatening lung infection, just to 'ease' the CESA process en-route to the surface.

Having too many 'options' actually decreases your chances of survival. It causes brain engagement and consequently delays the process. The CESA should be instinctive, immediate and without delay. The same goes for any emergency procedure.

If you doubted your capacity to CESA effectively from your planned diving depth, then you should have sufficient alternative/redundant air source instead.

 

[jago]

To my mind, it is a technic which needs training in order to be efficient in emergency situation, like the coralator method to handle a out of buoyancy emergency (injecting air in the crotch of the 2 pieces wet-suit and purge with the flanged).
But nowadays, there are many solutions to solve this type of issue.

How many is the value of your life ?

 

[AfterDark]

Practice CESA often until it's 2nd nature or don't depend on it. Being alone at 50ft without air tends to be distracting, whatever your going to do you want to do it well.

 

[GrumpyOldGuy]

Practice CESA often until it's 2nd nature or don't depend on it. Being alone at 50ft without air tends to be distracting, whatever your going to do you want to do it well.

Practice is generally a good idea, but CESA itself carries it own risk and the comment about being alone at 50' might be misleading. I have a few suggestions, others with more knowledge might have more.

1) Don't practice alone, your buddy should be right next to you.
2) Make sure your buddy understands an agreed upon max ascent rate, that he will monitor the rate and take action to slow you down if needed
2) Don't remove the reg from you mouth & keep exhaling slowly the entire time.
3) Decide if your profile is appropriate to allow a direct ascent without any stops.
4) Monitor your ascent rate - its not a race

 

[master00sniper]

Maybe I should have been a bit more specific with a bit less information.

For one I'm not over weighted when I dive. Full tank, holding a normal breath holds me right about eye level on the water. Its not so much that I have a lot of air in my BC when I'm down there, its that it turns into a lot of air when 50 feet shallows to 15 feet.

I probably should have just written, is it in any situation a good idea to attempt to get an emergency breath from your BC on your way up from an OOA emergency. It looks like the answer is no.

I've read that air expands in your hose when you go up. I never knew how much though. Thank you grumpy for answering that one. Seems to me the only way to really test that answer would be to actually create an OOA emergency by turning of your tank valve and ascending. I'm not that curious

Also I figured the air would be bad, I didn't think it would be as bad as Devon and vjanelle stated. Thank you both for answering that one.