CESA theory

[Dody]

While you insult regulars on the forum who go out of their way to help you and others, I spent 15 seconds on Google to find an average residual lung volume in adult males is 1.2 liters. See earlier answer to your question, do basic math and come up with at 20m expansion will allow a .4 liter exhale.. by 10m another .8liters will be available to exhale. By the surface another 1.2 liters of exhale. Regards nitrogen dissolved into your blood, if you are within NDL it won't be supersaturated and will remain in solution (as in not get bent).
People are concerned that you don't know this, not to be mean... But because as a DM you are in a position of authority and responsibility where you should already have a thorough grasp of this. So please don't attack .. listen.
Respectfully,
James

Your response is spot on. Not the judgement. My question was not about gas theory that everyone knows from OW. It was about real circumstances. and what I did not have for my calculation was the residual volume.

 

[Blackcrusader]

If you are capable of precisely telling me how much air you have in your body after a normal exhale at 30 m and exactly how and in which quantity it expands (blood and lungs) during the ascent and how much is available to exhale, I will stop thinking you are a world champion… and you will have answered my initial question.

Dody how much air you have cannot be measured. How much is your lung capacity and how would you even guess what you have after exhaling. I played wind instruments for many years so we were trained on slow long exhales when playing music. Also the issue is what your brain is telling you about breathing yet ignoring that and ascending on near empty lungs before re-breathing from a BCD.

Lets leave out the Einstein bits and think like a mere mortal that we all are. What can a mere mortal do to save ones own life, quite a lot really. I am not going to be worried about the gases in my blood stream on an NDL dive if I have to ascend. There is no requirement for a safety stop and even if I had some DECO obligation DCS can be treated if you did not grab another tank and descend to depth immediately. There are no world champions when it comes to saving your own life, by yourself from whatever depth you happen to be on in a dive.

 

[Dody]

My earlier post seems to have been completely ignored, so I will repeat the main point.

The navy procedure for submarine escapes is to exhale fully before beginning a submarine escape and then continue to exhale all the way to the surface. This has been done at depths to 300 feet.

I did read your post. But I was skeptical that normal individuals could be compared to navy professionals.

 

[Dody]

Your response is spot on. Not the judgement. My question was not about gas theory that everyone knows from OW. It was about real circumstances. and what I did not have for my calculation was the residual volume.

And I never insulted anyone trying to help me. I only responded harshly to people whose sarcasms are badly placed and who should expect a not happy response.

 

[Blackcrusader]

Your response is spot on. Not the judgement. My question was not about gas theory that everyone knows from OW. It was about real circumstances. and what I did not have for my calculation was the residual volume.

I am not talking about OOA due to lack of air in the cylinder but more a 1st stage failure. Thank you.

OK look at the video. Ist stage is blown. It does not mean there is no air in the tank. There is plenty of gas available so how do you get it into your lungs. You can remove the first stage and get air from the tank into your DSMB. You could breathe the air from your DSMB that you got from your tank. No need to do a CESA, no need to rebreathe from your BCD. What you need to do is think about how can I safely save myself. Who cares if some water gets into the tank?

Also a first stage failure does not mean that no air can get into your BCD.

In your opening your limit was thinking only about a CESA when there are other means. Take the least stressful and safest option. A slow ascent taking air from your DSMB would also work. Inhale exhale like normal and do a normal controlled ascent no need to do a fast ascent. In real circumstances the last thing I would be thinking about is how many liters of air I have in my lungs.

 

[James79]

And I never insulted anyone trying to help me. I only responded harshly to people whose sarcasms are badly placed and who should expect a not happy response.

The only judgement I have of you is of insufficient professional knowledge as a DM. I have no particular judgement of you as a person. As to "never insulted anyone trying to help you";

You are thick, aren’t you?

Try to understand the question before playing the expert… that you are not.

Read the thread carefully. At least try to understand. Obviously you have not.

Both of the gentlemen you addressed in the above quotes were trying to bring your attention to knowledge you already have (or should have).... and you snapped at both as though they are fools. They are both respected in this online community, precisely because of the amount of help and knowledge they share here. Literally in less time than you spent typing the insults to them, I googled "residual lung volume" and got you the answers you expected them to spoon feed you.
Again, you list your self with a professional rating. If I can help bridge a gap in knowledge I will help... but it gets awful hard to justify when you attack those who don't do all your research for you.
Please think about trying to request information (and even correct a misunderstanding of what you are looking for) with courtesy.... you are asking for help, and berating those who try doesn't encourage good results.
Respectfully,

James

 

[boulderjohn]

I did read your post. But I was skeptical that normal individuals could be compared to navy professionals.

Okay, so the navy people exhale first and then ascend to the surface exhaling all the way. They have done it from 300 feet. Can you explain how "normal individuals" are biologically different from these superhumans?

 

[Blackcrusader]

The only judgement I have of you is of insufficient professional knowledge as a DM. I have no particular judgement of you as a person.
Respectfully, James

Dody did a DM course that I believe was done in 2 weeks in Thailand. He had yet to do any night dives. At one place where I dive the same course would have taken 2 - 3 months and you had to lead several night dives. If his DM knowledge is insufficient then perhaps Dody should look at the course he did and wonder if he really got the proper training for his certificate. There are places in SEA that pump out certificates as people want to get certified in the shortest possible time.

 

[Blackcrusader]

Okay, so the navy people exhale first and then ascend to the surface exhaling all the way. They have done it from 300 feet. Can you explain how "normal individuals" are biologically different from these superhumans?

They aren't superhumans. They are trained. Not all navy personal are good swimmers. Technique and training are critical just as it is in your industry. People are trained for rescue and fires without being firemen or nurses.

 

[Dody]

OK look at the video. Ist stage is blown. It does not mean there is no air in the tank. There is plenty of gas available so how do you get it into your lungs. You can remove the first stage and get air from the tank into your DSMB. You could breathe the air from your DSMB that you got from your tank. No need to do a CESA, no need to rebreathe from your BCD. What you need to do is think about how can I safely save myself. Who cares if some water gets into the tank?

Also a first stage failure does not mean that no air can get into your BCD.

In your opening your limit was thinking only about a CESA when there are other means. Take the least stressful and safest option. A slow ascent taking air from your DSMB would also work. Inhale exhale like normal and do a normal controlled ascent no need to do a fast ascent. In real circumstances the last thing I would be thinking about is how many liters of air I have in my lungs.

Ok. One thing about first stage. In this case, there was something bursting it seems. Now, 1st stage can just fail blocking all air flow. I know that most should fail open but it happens that it fails closed, right or wrong?