70 replies to this topic

[Bubble2Bubble]

So the use of Nitrox is to limit the nitrogen from entering are bodies.

So Lets Talk Nitrogen

sense we are all created differently I hope its safe to say that we must absorb and ex spell nitrogen at different rates. I am sure that's why they have a somewhat standard safety stop times set-up for general use for all divers. but is there a way to test a divers ability to absorb and ex spell nitrogen? because If I knew for sure that I was not able to ex spell nitrogen because of scaring, fatty tissue etc. Nitrox would be the safest gas to use for all my diving needs shallow or deep. on the other hand if I ex spelled nitrogen at a faster rate than average because of some reason then Nitrox would be no benefit to me at all if I followed the normal safety stop recommendations. I don't think I can Google the answer either.

Is there a test that a diver can take to measure they ability to ex spell nitrogen?

B2B

[gcbryan]

So the use of Nitrox is to limit the nitrogen from entering are bodies.

So Lets Talk Nitrogen

sense we are all created differently I hope its safe to say that we must absorb and ex spell nitrogen at different rates. I am sure that's why they have a somewhat standard safety stop times set-up for general use for all divers. but is there a way to test a divers ability to absorb and ex spell nitrogen? because If I knew for sure that I was not able to ex spell nitrogen because of scaring, fatty tissue etc. Nitrox would be the safest gas to use for all my diving needs shallow or deep. on the other hand if I ex spelled nitrogen at a faster rate than average because of some reason then Nitrox would be no benefit to me at all if I followed the normal safety stop recommendations. I don't think I can Google the answer either.

Is there a test that a diver can take to measure they ability to ex spell nitrogen?

B2B

There is a test to measure one's ability to spell expel. It's called a spelling test
(Just kidding around here).

The 3 minutes safety stop is just to make sure everyone's ascent rate is slow enough and not to account for differing offgassing rates amoung a group of divers.

Nitrox would not be the safest gas to use shallow OR DEEP regardless of your offgassing rate. As you get deeper the PPO2 will be toxic at some point (will vary with individuals however).

I don't believe your rates of offgassing nitrogen are going to be markedly different than anyone else's. The pressure will be the same. You may have less or more fatty tissues but nothing in diving is specific enough to account for one individual. Deco theory is not exact (at all).

So whether or not there is a test that would measure your ability to offgas nitrogen I don't believe it would make that much difference unless it was realtime (displayed on your dive computer).

Edited by gcbryan, 24 June 2006 - 05:05 PM.

[BradfordNC]

Deco theory is not exact (at all).

hence use of the word "theory"

Mike,
the offgasing of nitrogen takes place in the lungs with the gas exchange when you breathe.
but its your circulatory system that is transporting all that nitrogen to your lungs for exchange.

scars, fatty tissue, et al, wouldn't hinder or prevent that from taking place.

the nitrogen is held in your tissues by pressure, and that pressure will be the same for everyone.

as noted previosly, with the number of factors involved, it is impossible to tailor it to any one diver in particular.

even if you don't think you'll ever dive nitrox, the class is a good way to learn more of the science. the basic nitrox courses are just that, basic. but if you take an advanced nitrox course (mixes up to 100% O2) you realy get to learn the science and understand how it all comes together.

well, that was my experiance anyway. not to slam any agencies presentations.

[Desert_Diver]

. . . for my last trip the nitrox bill was $180.

Answer = CCR

nah, i don't feel like spending $15,000 on something i'd get limited use out of

It doesn't *have* to be exhorbitantly expensive, particularly if you're handy in the shop. It's 1890's technology, and you don't need a high-tech gas management computer and solenoids; the KISS works just fine. I like the KISS style 'cos there's very little to go wrong with 'em. My modified IDA-71y comes in under the weight as a steel '80, but gets 3+ hours dive time and cost me < $2K. One of the guys I know in Phoenix regularly dives a homebrew that he spent less than $500 on, put together out of plastic sewer pipe and collapsible hiker's water bottles. His largest expense was the two first stages & pony bottles.

Putting it on a plane is my only concern, so I'll probably rarely use it for anything but lake dives.

[BradfordNC]

It doesn't *have* to be exhorbitantly expensive, particularly if you're handy in the shop. It's 1890's technology, and you don't need a high-tech gas management computer and solenoids; the KISS works just fine. I like the KISS style 'cos there's very little to go wrong with 'em. My modified IDA-71y comes in under the weight as a steel '80, but gets 3+ hours dive time and cost me < $2K. One of the guys I know in Phoenix regularly dives a homebrew that he spent less than $500 on, put together out of plastic sewer pipe and collapsible hiker's water bottles. His largest expense was the two first stages & pony bottles.

hmmm, something about anybody wanting to represent themselves in court having a fool for an attorney
and again, spending time, money and energy on something i'd get extremely limited use of.

Putting it on a plane is my only concern, so I'll probably rarely use it for anything but lake dives.

lake dives, wow, bet thats as fun and exciting as a quarry dive.
can't take it on a plane, doesn't do me much good

gets 3+ hours dive time

3+ hour lake dives. oh yeah, sign me up..... NOT

you don't need a high-tech gas management computer and solenoids

you don't need a doctor to perform a vasectomy either. but who do you want cuttin yo sack?

[captsteve]

since i dive primarily in NC and most of the dives are between 80 and 140ft, nitrox is a valuable tool. Most of us use ean30, and will use ean28 on the slightly deeper dives. My steel faber 120lp and 108lp with ean30 gives me a good bottom time within the ndl. The nitrox cert is well worth the time and money.

[6Gill]

I don't believe your rates of offgassing nitrogen are going to be markedly different than anyone else's. The pressure will be the same. You may have less or more fatty tissues but nothing in diving is specific enough to account for one individual. Deco theory is not exact (at all).

So whether or not there is a test that would measure your ability to offgas nitrogen I don't believe it would make that much difference unless it was realtime (displayed on your dive computer).

There are many factors that effect off gassing and and different people on/off gas at different rates.There are case histories of people walking away from a dive that according to the tables whiles otheres end up in the chambers while diving within the limits of their tables/computers.Look at the number of cases that one person on the team gets bent while the other doesn't.Look at the wide range in profiles that you'll get from diving different computers.
A Patent Foramen Ovale(PFO) http://www.scuba-doc.com/pfo.htm will effect your ability to deal with inert gas and is found in a number of people(about 1 in 3).Then of course you've got all the other factors to take into account.
Deco is theory and there is no absolute right answer but the more information you arm yourself with the better decisions you'll make as a diver(IMHO)

[gcbryan]

I don't believe your rates of offgassing nitrogen are going to be markedly different than anyone else's. The pressure will be the same. You may have less or more fatty tissues but nothing in diving is specific enough to account for one individual. Deco theory is not exact (at all).

So whether or not there is a test that would measure your ability to offgas nitrogen I don't believe it would make that much difference unless it was realtime (displayed on your dive computer).

There are many factors that effect off gassing and and different people on/off gas at different rates.There are case histories of people walking away from a dive that according to the tables whiles otheres end up in the chambers while diving within the limits of their tables/computers.Look at the number of cases that one person on the team gets bent while the other doesn't.Look at the wide range in profiles that you'll get from diving different computers.
A Patent Foramen Ovale(PFO) http://www.scuba-doc.com/pfo.htm will effect your ability to deal with inert gas and is found in a number of people(about 1 in 3).Then of course you've got all the other factors to take into account.
Deco is theory and there is no absolute right answer but the more information you arm yourself with the better decisions you'll make as a diver(IMHO)

I agree. I just took his point to be that he would use Nitrox except for the fact that he was concerned that he may be so efficient in offgassing that Nitrox would be a waste.

Nitrox may or may not be so useful depending on circumstances but not getting certified because of not knowing his individual offgassing rate seemed to be to be missing the point.

[Bubble2Bubble]

well it was mentioned earlier by gcbryan that a slower ascent rate maybe the cure for everything. if a diver on there safety stop having the sufficient amount of air would be better off by ascending at a slower rate and using rapid breaths to off gas the nitrogen. you kinda have to read the first 4 or 5 post to get up to speed of the topic of this thread.

B2B

[gcbryan]

well it was mentioned earlier by gcbryan that a slower ascent rate maybe the cure for everything. if a diver on there safety stop having the sufficient amount of air would be better off by ascending at a slower rate and using rapid breaths to off gas the nitrogen. you kinda have to read the first 4 or 5 post to get up to speed of the topic of this thread.

B2B

I'm confused. What are you talking about and who are you responding to?

Edited by gcbryan, 05 July 2006 - 07:36 PM.

[Bubble2Bubble]

Sorry about that. I'm still not sure what I was trying to point out either. I think I have been trying to post two subjects into one thread. It's possibble, I need to start another thread intitled "Off Gasing Techniques and Safe Diving Habits". Thank you everyone for contributing to this thread about nitrox and it's pros and cons of using it. maybe this will shed alittle light on the subject so people can learn more about it.


B2B