Do you think Nitrox is a deep diving gas?

[Walter]

Peter, it's actually 20.95. Calling it 21 is the result of rounding, not actually enriching mix. by .05% O₂

 

[Coldwater_Canuck]

Yes and no. I mean I know one of the most common things typed on here to new divers is "Nitrox isn't for deep diving" or some similar statement. Obviously, they are referring to the fact that your maximum depth decreases. However, I do generally think of Nitrox as more of a "deep diving" gas simply because unless you're diving all day long, it is hard to hit NDC limits at 60 feet or less using standard equipment (obviously doubles or a 130cf tank could change this). I have trouble believing most divers going to 60 feet on an AL-80 on up to 3 dives would manage to exceed NDC limits assuming a reasonable surface interval (even when I'm not worried about NDC, my surface intervals are usually at least 30 -60 minutes).

So when I say it's a deep diving gas, it's not that I think it lets you go deeper, but rather its main usefulness is at somewhat deeper depths.

 

[MXGratefulDiver]

Peter, it's actually 20.95. Calling it 21 is the result of rounding, not actually enriching mix. by .05% O₂

There are some nits that simply aren't worth picking ...

... Bob (Grateful Diver)

 

[MXGratefulDiver]

Yes and no. I mean I know one of the most common things typed on here to new divers is "Nitrox isn't for deep diving" or some similar statement. Obviously, they are referring to the fact that your maximum depth decreases. However, I do generally think of Nitrox as more of a "deep diving" gas simply because unless you're diving all day long, it is hard to hit NDC limits at 60 feet or less using standard equipment (obviously doubles or a 130cf tank could change this). I have trouble believing most divers going to 60 feet on an AL-80 on up to 3 dives would manage to exceed NDC limits assuming a reasonable surface interval (even when I'm not worried about NDC, my surface intervals are usually at least 30 -60 minutes).

So when I say it's a deep diving gas, it's not that I think it lets you go deeper, but rather its main usefulness is at somewhat deeper depths.

Someone who goes from Seattle ... where it's common to take nitrox as part of your OW class ... to Catalina Island ... where it's quite difficult to get nitrox ... can attest to the fact that for recreational dives deeper than 60 feet, nitrox is indeed a "deep" gas. For profiles similar to what we're used to doing at home, it's all too easy for NDLs to start limiting your bottom time.

Doing three reasonable dives at Casino Point on air was almost painful ... by the end of the third dive I had to stay in the shallows for a total of 26 minutes just to clear my computer of it's "deco obligation" (which I did because I wanted to use it the next day). With EAN32 I could've done those exact same dives without accruing any "deco obligation" whatsoever.

In both places ... Casino Point and most dive sites in Puget Sound ... it's very easy for the typical recreational diver to get to reasonably deep depths and remain there for the majority of their dive.

It still amazes me ... considering how many people travel to Catalina Island to go diving ... that nitrox isn't more readily available there.

To my concern, the greatest benefit of nitrox is for people who are going to be doing multiple dives a day in the 70-100 foot range ... simply because in that range it allows you to either extend your bottom time or reduce your surface intervals without having to worry about pushing your NDLs.

... Bob (Grateful Diver)

 

[DandyDon]

I recently went diving with a group of AOW divers and the topic: " Is Nitrox diving with oxygen contents above 21% a deep diving gas in the 99 fsw (30msw) and deeper range", came up on the way out. The opinions in the conversation were educational to say the least - So what do you think is Nitrox a deep diving gas?

Nitrox is Nitrox. I voted for all 3. Are you Nitrox certified...?

 

[dannobee]

There are some nits that simply aren't worth picking ...

... Bob (Grateful Diver)

True, especially since it varies with temperature and humidity anyway. Your reading will vary by the end of the hour.

If you can increase your NDL in the range (99-140fsw), couldn't one argue that it is indeed a "deep" gas? You just have to pay closer attention to the partial pressure(s).

If we're arguing to simply argue, remember that GUE standard mixes are 32% and a percentage of helium (irrespective of that 25/25 or something).

I think instead of calling it a "nitrox" class, it should have been labeled something else, since the gist of the class emphasizes partial pressures and depths.

 

[Coldwater_Canuck]

Someone who goes from Seattle ... where it's common to take nitrox as part of your OW class ... to Catalina Island ... where it's quite difficult to get nitrox ... can attest to the fact that for recreational dives deeper than 60 feet, nitrox is indeed a "deep" gas. For profiles similar to what we're used to doing at home, it's all too easy for NDLs to start limiting your bottom time.

Doing three reasonable dives at Casino Point on air was almost painful ... by the end of the third dive I had to stay in the shallows for a total of 26 minutes just to clear my computer of it's "deco obligation" (which I did because I wanted to use it the next day). With EAN32 I could've done those exact same dives without accruing any "deco obligation" whatsoever.

In both places ... Casino Point and most dive sites in Puget Sound ... it's very easy for the typical recreational diver to get to reasonably deep depths and remain there for the majority of their dive.

It still amazes me ... considering how many people travel to Catalina Island to go diving ... that nitrox isn't more readily available there.

To my concern, the greatest benefit of nitrox is for people who are going to be doing multiple dives a day in the 70-100 foot range ... simply because in that range it allows you to either extend your bottom time or reduce your surface intervals without having to worry about pushing your NDLs.

... Bob (Grateful Diver)

Ya, exactly what I meant. That 70-100 foot range is probably around where it starts to make a lot of sense. Under 60, it's tough to hit the limits (I guess if you're doing 4 or 5 dives a day or have a good SAC it's possible), over 100, the oygen content needs to be so low there isn't too much additional benefit (I guess EANx26 or whatever is still better than air though).

I've yet to use Nitrox because most of my dives are only 2 tank dives and anytime I dive past 60, the next dive is less than 60. I've yet to come anywhere close to hitting a NDC limit. But hopefully once I get back to Seattle and can dive more regularly I will do some 3 tank dives since it's more bang for your buck (in my case since I'm using Zipcar to get to the site, the major cost is the same whether I do 1 or 5 dives that ay). In that case depending on depth, I may want to use it.

 

[Blackwood]

remember that gue standard mixes are 32% and a percentage of helium (irrespective of that 25/25 or something).

30/30

 

[MXGratefulDiver]

over 100, the oygen content needs to be so low there isn't too much additional benefit (I guess EANx26 or whatever is still better than air though).

At a max PPO2 of 1.4, EAN32 is good to 111 fsw (or 110.88 if you're Walter) ...

... Bob (Grateful Diver)

 

[dannobee]

At a max PPO2 of 1.4, EAN32 is good to 111 fsw (or 110.88 if you're Walter) ...

... Bob (Grateful Diver)

Or 107 ft if you're diving a Suunto.