Nitrox instead of air for lower DCS risk?

[BigJetDriver]

-The safest way to use Nitrox is to dive it for what it is: Nitrox. It is not air so do not use air tables. That is the lazy person's way and can get you in trouble. Those who recommend using air tables either don't understand the gas themselves, or they don't think others can. Understand the gas you are breathing, or don't use it.

Good diving.

Artic,

I appreciate your repeating in so many words what I had said earlier. What you say in the partial quote above is not by any means correct, however, and needs to be amended.

The use of Nitrox on an air schedule table in recreational diving is a valid and well-established procedure. There is nothing "lazy" about it. What you are doing is simply using your air exposure times, and disregarding the fact that you have less nitrogen in the breathing gas, and therefore less inert gas loading at the end of the dive. This is where the statistical improvement of safety that I spoke of comes in. The diver who chooses this does so for reasons of personal conservatism.

Obviously, the diver who is choosing this method does so for a particular reason, understands the concept, and recognizes that the two standard mixes have depth floors or MOD's that cannot be exceeded, as I stated earlier.

I don't know when you started using Nitrox or mixed gases, but in 1995 when I took gas blending from Dick Rutkowski himself, he noted that NOAA had been doing the above since 1979, as well as using it (Nitrox) on its own schedule. I don't mean to be cynical, but I suspect Dick understands the whole concept better than you do. So, no, it is NOT the lazy man's way, and yes, people who recommend it DO understand it and do so for a reason.

To paraphrase Mr. Natural: "Get the right tool for the job, Kids!" :doctor:

 

[BigTuna]

What you are doing is simply using your air exposure times, and disregarding the fact that you have less nitrogen in the breathing gas, and therefore less inert gas loading at the end of the dive. This is where the statistical improvement of safety that I spoke of comes in. The diver who chooses this does so for reasons of personal conservatism.

Obviously, the diver who is choosing this method does so for a particular reason, understands the concept, and recognizes that the two standard mixes have depth floors or MOD's that cannot be exceeded, as I stated earlier.

What BigJetDriver said. Thanks, BJD.

 

[ArcticDiver]

Artic,

I appreciate your repeating in so many words what I had said earlier. What you say in the partial quote above is not by any means correct, however, and needs to be amended.

The use of Nitrox on an air schedule table in recreational diving is a valid and well-established procedure. There is nothing "lazy" about it. What you are doing is simply using your air exposure times, and disregarding the fact that you have less nitrogen in the breathing gas, and therefore less inert gas loading at the end of the dive. This is where the statistical improvement of safety that I spoke of comes in. The diver who chooses this does so for reasons of personal conservatism.

Obviously, the diver who is choosing this method does so for a particular reason, understands the concept, and recognizes that the two standard mixes have depth floors or MOD's that cannot be exceeded, as I stated earlier.

I don't know when you started using Nitrox or mixed gases, but in 1995 when I took gas blending from Dick Rutkowski himself, he noted that NOAA had been doing the above since 1979, as well as using it (Nitrox) on its own schedule. I don't mean to be cynical, but I suspect Dick understands the whole concept better than you do. So, no, it is NOT the lazy man's way, and yes, people who recommend it DO understand it and do so for a reason.

To paraphrase Mr. Natural: "Get the right tool for the job, Kids!" :doctor:

Gee guess we've found another place we disagree. The fact is that when a person dives with nitrox on air tables they are disregarding any tracking of oxygen loading. Or, in other words, the likelyhood of oxygen toxicity or airway compromise. That these are not likely is not the issue. The issue is proper and complete planning for a safe dive. Further, they are establishing a bad practice of treating a particular mix of gas as something it is not. Further, many of the people I have dove with on tourist boats and who are using nitrox with air tables actually don't understand what they are doing. They were taught that using nitrox with air tables is the "safest thing to do". This may work in many cases. But, oxygen is not a benign chemical. It has definite and significant effects on the body that need to be accounted for.

Quite the contrary, the safest thing to do is use whatever breathing gas the diver chooses according to the data that applies to that breathing gas. That includes proper quality control, labeling, measuring and dive profile calculation. Not only will that result in the safest dive; it establishes the safest practice of always planning the dive with the best data available.

As you said use the right tool for the job. In this case that right tool is the correct table for the breathing gas selected.

 

[H2Andy]

Gee guess we've found another place we disagree. The fact is that when a person
dives with nitrox on air tables they are disregarding any tracking of oxygen loading.

lol... not if they know what they are doing. any time you dive with Nitrox,
whether you are planning on air NDL's or Nitrox NDL's, you should ALWAYS
have your MOD and 02 loading as primary planning considerations.

now YOU may disregard those. i sure as heck don't.

Quite the contrary, the safest thing to do is use whatever breathing gas the diver chooses according to the data that applies to that breathing gas.

you don't say? pray tell, what is the name of 21% Nitrox? (it's air). your
argument would make sense if you're talking diving trimix vs. diving nitrox,
but it makes no sense in air (nitrox) v. nitrox (nitrox).

so you use a different set of NDL's, big deal ... as long as those NDL's are safe for
the mix you are using (and they WILL BE 100% SAFE if you dive a hotter mix
but plan for air NDL's), you're ok. in fact, you're better than ok. you're safer, as
long as you undersand Nitrox planning and take all due factors into consideration.

and, you know, it's not rocket science. heck, even *i* can do it.
how hard can it possibly be?

 

[Skeeter1097]

Here is one for all of you. I was told that in time as you age. People that dive nitrox has less boine and hip problems later in years thin some one whome did not dive nitrox. a study by the U S NAVY.

 

[Tom Winters]

You really want to do your old bod a favor - start squirting some helium in the mixture. If you dive 30/30 - one of the standard trimix formularies, there's only 40% nitrogen in there with the helium and oxygen sharing the honors. There's probably trimix classes all over the place up there in New Jersey.
It's gets expensive though - $.30/cubic foot down here, but there's always the homebrew option.

 

[Derek S]

You really want to do your old bod a favor - start squirting some helium in the mixture. If you dive 30/30 - one of the standard trimix formularies, there's only 40% nitrogen in there with the helium and oxygen sharing the honors. There's probably trimix classes all over the place up there in New Jersey.
It's gets expensive though - $.30/cubic foot down here, but there's always the homebrew option.

Tom -

Don't you think that telling a diver with less than 50 logged dives to go Trimix is a bit premature?

 

[ArcticDiver]

lol... not if they know what they are doing. any time you dive with Nitrox,
whether you are planning on air NDL's or Nitrox NDL's, you should ALWAYS
have your MOD and 02 loading as primary planning considerations.

now YOU may disregard those. i sure as heck don't.



you don't say? pray tell, what is the name of 21% Nitrox? (it's air). your
argument would make sense if you're talking diving trimix vs. diving nitrox,
but it makes no sense in air (nitrox) v. nitrox (nitrox).

so you use a different set of NDL's, big deal ... as long as those NDL's are safe for
the mix you are using (and they WILL BE 100% SAFE if you dive a hotter mix
but plan for air NDL's), you're ok. in fact, you're better than ok. you're safer, as
long as you undersand Nitrox planning and take all due factors into consideration.

and, you know, it's not rocket science. heck, even *i* can do it.
how hard can it possibly be?

Talk about selective understanding, you just demonstrated it

Now I'm not saying they don't exist, but I've never seen any Air tables or computers that track oxygen loading when they are set on Air. Usually that is the default setting and doesn't even say Air. Sure they will if they are in the Nitrox Mode and set on 21%. But that isn't what folks do when they dive nitrox on Air.

So, you and I wouldn''t dive nitrox without keeping track of oxygen loading but loads of people do when they use the Air tables as one of the options they were erroneously taught.

The issue isn't MOD or NDL. That is generally taken care of when the diver analyzes the tank and enters the data in the shop/boat log and on the tank label. So that isn't even close to the issue I'm talking about.

 

[BigTuna]

The fact is that when a person dives with nitrox on air tables they are disregarding any tracking of oxygen loading.

Not me! I'm a responsible diver, and your posts make clear you are, too, and want everybody to be, as well.

But without scuba cops, the best we can do is hope that anyone using Nitrox is certified in its use, understands the additional risks it introduces, and has his or her brain engaged at all times, especially regarding nitrogen, oxygen, decompression, toxing, and narcing.

 

[H2Andy]

So, you and I wouldn''t dive nitrox without keeping track of oxygen loading but loads of people do when they use the Air tables as one of the options they were erroneously taught.

ah.... so.... diving Nitrox on air NDL's is dangerous because some people don't
follow proper Nitrox training?

ok.... well... then all Nitrox diving is dangerous, since those people are not
going to follow proper Nitrox training

by this logic, since divers won't follow proper Nitrox training, we should
eliminate Nitrox and dive only air.

the issue which you continue to try to complicate, is that if you dive Nitrox
with air tables and otherwise follow Nitrox training, your dives will be safer
DCS-wise, since you will be diving at a "shallower" depth and will have
a bigger margin of safety.