Nitrox the Wonder Gas

[Twiddles]

Still researching for safety stops and happened across this article, was more than a bit surprised by the statements made. http://www.scubadiving.com/article4545

What Nitrox Won't Do
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."

Claim #2
Less gas consumption. This sounds reasonable too. If there's more oxygen in each breath, presumably you don't have to take another one so soon and your gas consumption rate is lower. Unfortunately, it doesn't work that way because most of the oxygen you breathe is exhaled unused anyway. What drives the next breath is the need to exhale carbon dioxide, and that's not affected by what's in your tank.

Claim #3
Less fatigue. "Those long and tiring drives returning from a day of diving are over!" enthuses one dive shop's web site on the benefits of diving on nitrox. Is it really the "feel good" gas? The theory here is that the work of offgassing nitrogen is a major cause of diving fatigue, so less of it should leave you less tired. Many nitrox divers swear it's true, but Bennett cites a blinded study that proved otherwise. Using unmarked tanks, one group of divers was given nitrox, another was given air, and both were asked later how they felt. "There was no difference," says Bennett. "It's a placebo effect."

Claim #4
Deeper dives. Some divers think those green-and-yellow cylinders look serious and "techie," and associate that with going deep. In fact, nitrox introduces a new depth floor that's often shallower than the 130 feet we're used to. PADI's recommended depth limits are 110 feet for 32 percent nitrox and 95 feet for 36 percent nitrox. The penalty for going below the floor is serious, too. Many of us would risk chasing that eagle ray down to 150 feet on air (NO I WOULDN'T), but wouldn't think of it on nitrox.

 

[Doc]

Still researching for safety stops and happened across this article, was more than a bit surprised by the statements made. http://www.scubadiving.com/article4545.

If you keep reading from that website, your "surprised meter" should well go off the scale. They print the darndest things!

 

[Wayward Son]

 

[Twiddles]

Dr. Bennett is the founder of DAN, and his credentials... well Im not really certain what you need but he has more than enough for me . If you link his name and diving Nitrox in google its obvious that the article did not misquote or misrepresent his "expert" opinion.

 

[ghostrunner007]

Oh Boy here we go again

 

[Guba]

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!

 

[do it easy]

While we are at it, I think that nitrox is more narcotic than air! I don't subscribe to the "well, the O2 is metabolized, so it doesn't affect narcosis" school of thought. Admittedly, I haven't done any double blind, controlled studies.

 

[Alian1]

To the OP, What statements surprised you so much? It seems to make perfect sense to me?
Could you elaborate?

 

[Divin'Papaw]

While we are at it, I think that nitrox is more narcotic than air! I don't subscribe to the "well, the O2 is metabolized, so it doesn't affect narcosis" school of thought. Admittedly, I haven't done any double blind, controlled studies.

I thought you were an actuary? Come on, where's the data?!

 

[Divin'Papaw]

It's a tool, not a silver bullet. Sometimes it makes sense, many times it doesn't. Understand the physiology and the pros/cons and then decide accordingly.