Nitrox vs. Regular Air?

[granolatree]

Not sure if this is the right place to post this question, but I couldn't find any thread for Nitrox questions! (Am I just blind?)

Lately we have been going around to different shops asking about their different philosophies on equipment, air, etc. Why is it that some shops are pushing Nitrox, and in some cases giving a better deal on Nitrox than air? Are there any long term benefits of diving with Nitrox? I've been told of the benefits of diving deeper with Nitrox (longer bottom time, shorter decompression stops, less fatigue after the dive, etc), but would it be beneficial for your typical recreation diver to use Nitrox as well?

The owner of one of the shops in town won't even let his employees dive with regular air unless they are just going to be in a pool training. Other than that, it's either Nitrox, or going to a different shop to fill their tanks! One of the other shops in town, they say that Nitrox is for the technical diving crowd, and not to even waste the extra money if you are just going to be rec. diving.

Any thoughts?

 

[Jimmer]

Well define your idea of recreational? Personally I use Nitrox anytime I'm going to be deeper than 50 feet or so. I find past that depth, Nitrox makes a lot of sense to me. Partially for longer BT's, shorter surface intervals, or for a greater margin of safety. What I mean by that is breathe Nitrox, but follow air tables for that depth, and you will always be looking at a safer profile. I think Nitrox absolutely benefits recreational divers.

Jim

 

[tridacna]

Oh boy. This should be fun!

(Hint: There are M A N Y threads on this. Try and search again).

 

[granolatree]

I'm assuming this is another one of those controversial topics? Haha! I will do another search...

Jimmer:
Is there a reason you don't use it in less than 50 ft.? Would that be because of cost, or because you don't need to decompress much? I guess, decompression really just depends on how long you stay down, doesn't it? As far as "recreation diving" goes, I would say that it would (for me) just be swimming around, checking out marine life and what not. Nothing too technical about it. If I were to wreck dive or cave dive, I could see the benefits of Nitrox as I would want a longer BT. As a beginner diver, would it be beneficial for me to use Nitrox when I am not going down very deep? What all does the Nitrox certification entail?

Okay- off to go search the board again...

 

[1_T_Submariner]

Take the class if they are offering it for a reasonable price (like $100 or so). If you have a good instructor you will know when to use Nitrox and when to use air.

Personally I use nitrox when doing more than 2 dives a day (regardless of depth) and/or dives greater than 50 feet and less than 110 feet this is where nitrox will have the greatest benefit.

 

[ChrisA]

I think the truth is in the middle ground. Air is of course safe. There is some argument that nitrox is safer because there is simply less nitrogen in the mix but there are other samll risks and on balance when they measure accident rates and so on air and nitrox are just as safe. There is no observed statistical difference.

The advantage of nitrox is that the diver off gasses quicker. This is an advantage if you are doing multiple dives over either a long day or multiple days. If you work out a repetitive dive scenario you can see right away that you come out with lower pressure group letters. Yes in theory you can stay down longer but most people don't. They hit there turn around pressure before they hit NDL. Unless they have a large tank.

One or two pressure group letters don't mean much if you are doing one or two dives but on a week long vacation or a live-aboard I would recommend nitrox.

In your nitrox class you will learn the nitrox is NOT for doing deep dives. As you dive deeper your mix will look more and more like air. There is a sweet spot of about 50 to 110 feet where nitrox helps the most.

 

[Jimmer]

The reason I don't generally use Nitrox in less than 50 feet, is because the limits for air at that depth, are long enough for me to get a very satisfying dive length, without the need for Nitrox. Submariner makes some good points about using it on multi dive days, and also to look into taking the course. It's an affordable course, and you will be able to make your own decisions on that sort of stuff.

Jim

 

[granolatree]

Thanks for the info, all of that makes a lot of sense. If we come across a reasonably priced class, I'm sure we will sign up.

 

[peterbj7]

I'm wearing a tee shirt with the slogan "if you understood nitrox you'd be diving it too".

Says it all really.

 

[bleeb]

I'm assuming this is another one of those controversial topics? Haha! I will do another search...

In case you didn't find it, here's a sticky about Nitrox. As you can see, the discussion can be a bit 'heated'. http://www.scubaboard.com/forums/ask-dr-decompression/132610-nitrox-instead-air-lower-dcs-risk.html

And yes, various aspects of Nitrox have been somewhat .

But to answer your other question, I can't speak for Jimmer, but for me, it's not that you can't or shouldn't use Nitrox for shallow dives. It's the generalization that when you get shallower, you'll get so little if any benefit, that it's not worth any additional effort to use Nitrox (cost, extra effort getting the gas, keeping your tanks O2 clean, MOD, keeping track of your O2 clock, etc.) For instance, NDLs get long compared to tank size. But if the extra efforts aren't issues for you for a particular dive, go for it.