Do you think Nitrox is a deep diving gas?

[Sas]

But it does lead me to wonder what education the AOW people are getting if they think EAN mixes are for "deep" diving. Yes they are, of course, but with the caveats. Hmmm, maybe should be part of one of my lectures this week.

I was taught that nitrox reduces narcosis and therefore it was better to dive with a nitrox mix in the 30-40m range by my Deep instructor so yes, it was kind of sold to me as a "deep" diving gas in that regard early on as he said it would be safer as I would be less narced. My actual nitrox class instructor was in favour of trimix below 30m (and whilst beyond the scope of the course he did talk about this a bit), and EAN32 shallower than that so I was taught that nitrox is narcotic as well as air - and given my own experiences, I agree with this so do not see it as a deep diving gas (unless you are talking about how it can be used to accelerate deco for deeper dives but I thought that seemed out of the scope of what the people were saying as described by the OP).

There are no good arguments for NOT using Nitrox.

Cost. Here it is $5 for an air fill, $15 for a nitrox fill. I only use nitrox to extend NDL times on dives below 20m, not to reduce my risk of DCI. Either with air or nitrox, dives to those depths are going to be at the NDL so I personally do not see it as lowering my risk (which is already very small).

 

[Walter]

There are no good arguments for NOT using Nitrox.

Withing defined limits, I would agree. Without defined limits, this is a poorly thought out statement, silly at best. Within other defined limits, there are no good arguments FOR using nitrox. I use nitrox when it's the best tool for the dives I have planned. Then I'm collecting fossils at Venice Beach in less than 20 feet of water, nitrox offers no benefit, air is the gas I use. If I'm diving a wall with divers I don't know well, but for whom I have responsibility, I'll usually dive air to keep my options open in case one of them needs to be pulled up from too deep.

 

[MXGratefulDiver]

I was taught that nitrox reduces narcosis and therefore it was better to dive with a nitrox mix in the 30-40m range by my Deep instructor so yes, it was kind of sold to me as a "deep" diving gas in that regard early on as he said it would be safer as I would be less narced.

I have not, personally, found any difference in narcosis levels between nitrox and air.

These days almost all of my recreational dives are done on EAN32. I have one favorite dive I'll use EAN36, since almost the whole dive is spent at between 80 and 95 feet and it gives me a bit more bottom time. If I'm planning to go below 110 feet, I may go with a leaner EAN mixture or with trimix, depending on the dive. I only use EAN21 on very shallow dives (40 feet or less), or on my surface intervals.

... Bob (Grateful Diver)

 

[guamguy]

Nitrox is a gas with an optimum depth range. That optimum range is dependant on the % O2 in the mix. For some mixes, that optimum range would be inside, what recreational agencies classify as, 'deep' diving.

You hit the nail on the head. Any gas mix has it's MOD (maximum operating depth). To get deeper, you actually need LESS oxygen. If you are confused on this subject, take the nitrox course and it will all make sense in the end.

 

[Sas]

I have not, personally, found any difference in narcosis levels between nitrox and air.

Yes, that has been my experience also. But n=quite a small number for me diving nitrox But, I have been quite narced using nitrox so I know it is possible. Therefore I do not treat air any differently to nitrox in regards to narcosis.

 

[drl]

Given that the OP defined "deep" as ca. 99 feet, yes, nitrox is useful. Given the right mix it can be used at all recreational depths and does give extra bottom time. The biggest difference, though, is when you do multiple dives in a day. On the subsequent dives nitrox users can get significantly more bottom time than air users.
Of course, if your dive time is limited by your air consumption rather than available bottom time, it doesn't offer much benefit.

 

[Walter]

I only use EAN21 on very shallow dives (40 feet or less), or on my surface intervals.

Bob, you know better. While air is nitrox, it is not EAN, it lacks the E.

 

[Peter Guy]

Walter, Bob wrote EAN 21, NOT EAN 20.9! That extra 0.1% you know.

And Thal, yes, it IS part of the genius of my teaching plan.

 

[Tigerman]

Ah ... now I finally understand, you train incompetent, nervous divers so that their lack of comfort and high SAC rate keeps them from getting bent because they can't stay down long enough to really need to hold a safety stop. How ingenious.

I dont teach anyone diving as im not certified for that. I just have yet to see a diver fresh out of ow (who havent been diving uncertified anyways) with anything but rather bad SAC..

 

[MXGratefulDiver]

I dont teach anyone diving as im not certified for that. I just have yet to see a diver fresh out of ow (who havent been diving uncertified anyways) with anything but rather bad SAC..

Oh, I have.

Bad air consumption rates are due primarily to two factors ... lack of comfort in the water and poor technique.

The former can be remedied without scuba training at all ... for example, people who have spent a lot of time swimming and/or snorkeling prior to scuba training.

The latter can be remedied in a properly taught OW class. However, it will usually take more time and effort than is currently available in most commercially-available OW classes.

Then there are those with tiny bodies and/or lungs who just don't breathe much ... they will have pretty good SAC rates even without either comfort or technique. TSandM was one such when I first met her ... I was amazed at how little air she needed, considering how much she was struggling just to get and stay underwater. Now that she's acquired both comfort and technique, her air consumption rate would put her somewhere close to the marine mammal category.

... Bob (Grateful Diver)