Nitrox the Wonder Gas

[DandyDon]

ooops

 

[rockjock3]

Okay, I'm making my predictions now...
1) Those who use Nitrox will (having paid for the class, the computer and the tank) swear by how much it helps.
2) Those who have not gotten Nitrox certified will agree whole-heartedly with the good doctor's statements.
3) Virtually NO divers who are Nitrox certified will say it was a waste of time and money.

I have no stake in the outcome. I'm just curious to see how the discussion plays out. Now, let the games resume!

It helps a whole lot for me, and it lets me go way deeper for longer.

Of course I'm using the 50% and 100% nitrox mixes in my stages and not in my bottom gas.

 

[MXGratefulDiver]

I seriously doubt I will ever find the need to use Nitrox based upon what I have read.

I used to feel that way ... my first dive computer was air-only. I've since come to realize the benefits of nitrox (for me) and replaced that computer with one that handles nitrox.

If I ever do feel adventerous enough to get into tech diving,

Actually, the only place nitrox is used for tech diving is in deco bottles ... and that's typically in higher percentage mixes (e.g. EAN50, etc.)

I suspect most divers would be less than likely to accept a buddy who was on air if they were using Nitrox.

I would dive with you anytime ... happily. I regularly dive with newer divers on air, while I'm no nitrox. It's a non-issue ... the only consideration is the dive profile, which we both need to agree to before starting the dive.

... Bob (Grateful Diver)

 

[Thalassamania]

Most of the time I dive NITROX on air tables to decrease DCS probabilities. I do feel less fatigue, but that's a subjective judgment.

 

[The Kraken]

The only reason I dive Nitrox is because I can't find a place to give me a fill of Nitrous Oxide . . . .


One small matter here I'd like to address, and that's how one of the statments/myths is put forth:

"Claim #1
Nitrox reduces narcosis. This sounds reasonable. If nitrogen causes narcosis and you're breathing less of it, you should have less narcosis. The trouble is, the depth range where you start worrying about narcosis (100 to 130 feet) is also where you have to stop using nitrox because of the risk of oxygen toxicity. Dr. Peter Bennett, who co-edited The Physiology and Medicine of Diving and wrote the chapter on inert gas narcosis, says the preventive value of nitrox is "very small, so marginal that I think it should be discounted."

Generally I hear a Nitrox instructor say that Nitrox, at a given depth, reduces the ONSET of DCS as opposed to diving air at the same depth.

Logic:

If: At a given physical depth Nitrox effectively reduces the nitrogen equivalent of the dive. . .

Then: At that given depth there is less nitrogen to be absorbed into one's system . . .

Therefore: The reduced absorption of nitrogen effectively reduces the onset of DCS given equal dive depths and times Nitrox:Air . . .


the K

 

[String]

With me i dive air 95% of the time. Most of my diving i dont need to increase my non stop time or short deco hang time so its not worth the extra cost (typically 2-3x the cost of an air fill).

In addition it can also be limiting. On a boat here where you often dont know the site until already on the water gauging conditions it can mean you dont dive. If you've got a 32% mix trying to do a wall and reports come in of fantastic vis on a 40m wreck not far from there you're screwed - with nitrox you cant dive that wreck, with air you can do both.
Air (ie weak nitrox with a deep MOD) is more flexible in this respect.

Nitrox has its place but for my diving its an occasional use.

 

[String]

Therefore: The reduced absorption of nitrogen effectively reduces the onset of DCS given equal dive depths and times Nitrox:Air . . .

However, even if the above is true it would seem the difference (if it exists) is so small as to not be statistically measurable or statistically significant given studies that have tried to do just that.

 

[moxie]

dives a day, sometimes 4 or 5. With nitrox whenever possible. Extended bottom times are the main reason I use it. It does, in my opinion, lead to less fatigue at the end of a long dive day and especially after 6 or 7 days. "Geezer gas" in my case. I do think, no evidence, that gas consumption is a trifle lower with nitrox. I do think, no evidence, I'm a trifle warmer with nitrox. No opinion on narcosis. Negatives include the extra cost, the analysis process which can be a PITA depending on the op's setup, and carefully watching your MOD. I don't see ox tox as a real problem unless you spend considerable time right at your MOD, which is rare in sport diving. I did see a relatively new diver recently sink to about 120' on 36% for about 2 minutes after he popped out of a swim-through at about 90' before he figured out where he was. His Mares Air Lab integrated totally locked up over it and wouldn't even show depth or pressure. He knew, but forgot, to get right on his gauges when he popped out on the wall and to watch his MOD and establish his buoyancy. (He'd programmed his computer for a ppo2 of 1.4 with an MOD of 95' and knew the dive profile.) He probably won't make that mistake again. Another guy on the same dive, not on nitrox, dropped to about 150' before he woke up (luckily). Buoyancy is buoyancy.

All things considered, nitrox is the gas of choice for me for most common sport diving profiles. Many, many, experienced divers are fully aware of Dr. Bennett's findings but share the observations I've made above anyway.

 

[The Kraken]

However, even if the above is true it would seem the difference (if it exists) is so small as to not be statistically measurable or statistically significant given studies that have tried to do just that.

And that is good, and I applaud them, but this is the ONE statistic that I like about Nitrox:

Dive Depth = 80'

NDL Air = 30 min.
NDL EAN36 = 55 min.

25 minutes is sufficiently measurable for me !!!!

the K

 

[String]

Thats the no stop time. That may not be related to the safety effect. Nobody i know of is debating the increase no stop time with EANx.