A question from an 11 year old.

[Bob DBF]

Was that not the reason given for removing CO2 cartridges (emergency inflation) from BCD's back in the day?


Bob
-------------------------------
I may be old, but I’m not dead yet.

 

[Cave Diver]

A couple of older discussions for reference:

http://www.scubaboard.com/forums/basic-scuba-discussions/191898-bcd-breathing-bag.html

http://www.scubaboard.com/forums/basic-scuba-discussions/373634-breathing-bcd.html

http://www.scubaboard.com/forums/basic-scuba-discussions/133965-breathing-air-bcd-ooa-situation.html

 

[CuNanoTube]

I occasionally get ear infections from the water (lake Ontario mostly) I dive in. I cannot imagine what that would do to my lungs after sitting in a BCD bladder (you cannot reasonably get all the bacteria out) for months.

 

[tddfleming]

I swear I read a story some time ago from a guy who took a breath from his BC while getting it ready for a dive and ended up very sick and I think he ended up dying from the infection or maybe could no longer dive. I have been trying to find it but no luck yet. It may have been on diving accidents group.

 

[cloudflint]

Hmm im pretty sure I have an old frenzy lying around somewhere. What could possibly go wrong!

 

[DivemasterDennis]

Out of the moths of babes... Here is how to answer the question. " That's a really good point. But you should never have to worry about it, because if you ever do have an out of air emergency, you will (should) always be close enough to your buddy to just reach over and use his alternate air source." You might also say that "later on in training, after you have some diving experience, we will discuss more emergency procedures including the one you just mentioned. I really like how you are thinking about options in an emergency. That is really important to do, all the time."

Om the CO2 buildup, if the air in the bc came from the low pressure inflator, it is no different that what is in the tank. One good deep breath may make the difference in some unique circumstance. You can slowly exhale into the BC as needed, or not do so. The you can take a second breath if the air is there in the bc. I do agree, "in and out" breathing from the bc is not a good idea.
DivemasterDennis

 

[rx7diver]

You could technically breathe the air in your BCD in and out (using the bladder and not letting air escape). ... That being said... if I am OOA and in that bad of a situation, I wouldn't give a damn about future problems from germs and CO2. Deal with it later, would rather make it to the surface alive.
One of the guys mentioned that theoretically, if you are very low on air but still some left, you could breathe your BC for a while, dump then refill with air, breathe off that for a while, and so on until you run out. Should last longer then just breathing your tank

My first scuba instructor told us about some experimentation that was done with snorkels (maybe in the 1950's or early 1960's?). He said that the experimenters learned that snorkels that were either too long or had too large a bore were problematic because a skin diver was re-breathing too much of his exhaled air which remained in the snorkel tube. Oxygen was very quickly depleted with each subsequent breath, and carbon dioxide was very quickly increased. (Snorkels that are too long or too large are problematic for other reasons, too.)

I wonder if re-breathing from the inflator hose of a BC would present the same problem, especially if the inflator hose were very long (as some of them tend to be)?

Safe Diving,

Ronald

 

[melanie.]

My first scuba instructor told us about some experimentation that was done with snorkels (maybe in the 1950's or early 1960's?). He said that the experimenters learned that snorkels that were either too long or had too large a bore were problematic because a skin diver was re-breathing too much of his exhaled air which remained in the snorkel tube. Oxygen was very quickly depleted with each subsequent breath, and carbon dioxide was very quickly increased. (Snorkels that are too long or too large are problematic for other reasons, too.)

I wonder if re-breathing from the inflator hose of a BC would present the same problem, especially if the inflator hose were very long (as some of them tend to be)?

Safe Diving,

Ronald

Yes I am sure that would be a huge factor as well. But the way I see it, even if you only get 2 breaths you are alive 30 seconds longer then you would have been otherwise. You could also try and do this while rolling around in the water, forcing the air to mix as it always goes to the highest point of the BC

 

[Frosty]

Out of the moths of babes... Here is how to answer the question. " That's a really good point. But you should never have to worry about it, because if you ever do have an out of air emergency, you will (should) always be close enough to your buddy to just reach over and use his alternate air source." You might also say that "later on in training, after you have some diving experience, we will discuss more emergency procedures including the one you just mentioned. I really like how you are thinking about options in an emergency. That is really important to do, all the time."

Thanks guys --dennis--that is basicly EXACTLY what I said except I keep reminding them that its all "pre learning" they are doing now. Ie the real instructor will be able to answer propperly
I diddn't want to use the phrase one of the guys here used "Id breath out of the backside of a donkey if it meant that I get to the surface alive"
I'm discovering that "risk" really isn't something that teens and preteens concider. They have total trust in adults at the moment.

 

[dumpsterDiver]

Was that not the reason given for removing CO2 cartridges (emergency inflation) from BCD's back in the day?


Bob
-------------------------------
I may be old, but I’m not dead yet.

The cartridges contain too little gas to provide much more than a fart at depth. The cartridges could corrode and explode if left in say a car. The mechanisms would fail from corrosion if not well maintained. The threads of the cartridge would seeze up with the detonation mechanism.

They were a relic from when a mae west vest was used which is basically a inflatable pdf that was intended to be activated at the surface.

Remember these were popular before people ever got the idea of taking a pressure gage underwater with them....