Nitrox Advantages? Input Needed!

[Rik]

What are the Nitrox advantages and dis-advantages?
Is it time:
Is it better on the body?
Does it help with Narcoses?
Myth vs. reality?
I usually do 2 tank dives, what’s the advantage at dives between 60 - 100 feet?
Rik O+<

[Omicron]

Less narcosis is a myth...you are just as narced as with air. Most say it's because oxygen is just about as narcotic as nitrogen. And the amount of oxygen you add to the mix isn't enough to offset the nitrogen anyway...

Time is the biggest factor! Using just the PADI RDP's, here are the numbers:

Air - 60', 54 minutes. 100', 19 minutes.

EANx 36 - 60', 108 minutes. 100', 34 minutes.

You get HUGE bottom time increases. That is the main benefit of it.

Some say you feel better after diving with Nitrox than with air. Others say it's a placebo effect. Placebo or not, I'll take the effect because I usually don't have the post-dive "blahs" after using Nitrox somewhere in my dive. Whether that is because it's really helping, or I think it's helping...who knows, but I like the results.

The reality of Nitrox is that it only promises to increase bottom times. That's it. It's a great thing to use, and I'd definitely recommend taking the class. Dives in the 60-100 range get a huge benefit in NDL's from Nitrox.

[dfreeman]

Jason has it right. Increased bottom time is the main thing. I like using nitrox whenever I go below 70 feet, however I rarely have it available.

I also feel better after a dive on nitrox.

Doug

[divbum]

And shorter surface intervals....
Some distinations only give you x-mintues inbetween dives
How long to sit on beach before your next dive
Or whatever the reason your second dive will likely show more of an advantage then the first depending on air consumtions and all sort of varibles. Time for MNF and reasembly of a few regs I decided to service today...
Disadvantages - depth resitrictions of the gas if you show up for a 130 dive and your tanks are mixed for 90. Or the plan was 90 but its a great day lets go farther out to a deeper site...not an option. A little extra time and deadication, but it is worth is.
No need to repeate the correct info already posted.
Between 50-100 review any rdp's will show you the most advantages of the gas.

[matt t.]

Nitrox can also be used with air tables (with special regard to MOD) to add an extra safety margin. The DOWN side to Nitrox that I don't think anyone has mentioned yet is that it is 2-2 1/2 times the cost of air. Maybe not a big deal for a tank or 2, but when you fill 6 tanks at a time it does get expensive. There is also the annual cost of 02 cleaning each tank and valve. :

[ethanb]

When you go down to Florida,there are some places where Nitrox is the same price or even cheaper. Bill Rennaker's Cave Excursions banks 32-34% nitrox and sells it for $0.08/cubic foot. Air fills are $7 for a single tank and $14 for double tanks, flat rate. So, unless your tanks are near empty, a Nitrox top is generally cheaper than an air fill. For example, if my double 112 are half full (or is it half empty - either way that's fairly common after a typical cave dive), getting them topped with nitrox would be 112*0.08=$8.96, while getting them filled with air would be $14.

This last trip I did 18 dives in 9 days, with a total bottom time of over 15 hours. I definitely notice a difference with Nitrox - far less deco and my body feels much better.

Ethan

[fishchaser]

Do you mean two single tank dives, or you dive doubles?

Something to consider with all the extra bottom time you get with Nitrox is whether or not you can actually use it. Meaning, do you have enough tank volume to allow you to use all the bottom time that you're allowed?

To answer that, you'd need to know your RMV. I've calculated (poorly) my RMV for warm water and for cold water, 0.55 cu.ft./min (15.6 L/min) and 0.86 (24.5) respectively. At 60', with a 3000 PSI tank and finishing with 500 PSI, I'd have 43 minutes of air (or 28 minutes in cold water) in my 80 cu.ft. tank. At 100 feet, the 80 cf tank would run out in 30 minutes (19 minutes cold). (These numbers assume you are instantly at these depths, or at an average depth listed, so actual bottom times are not exactly correct.)

So, unless you dive doubles, you will not be able to get the bottom times listed in other posts in a single dive. But it would help in total bottom time vs. SI for repetitive dives.

Chad

[Omicron]

That's actually a pleasant problem to have - NDL's that outlast your tank volume.

[fishchaser]

True. But isn't it also the truth for air singles? (Most of the time.) I'm still a newbie, but for all of my dives to date, someone in the group (not me, the newbie!) has run out out of air before the NDL limits.

[matt t.]

When you go down to Florida,there are some places where Nitrox is the same price or even cheaper. Bill Rennaker's Cave Excursions banks 32-34% nitrox and sells it for $0.08/cubic foot. Air fills are $7 for a single tank and $14 for double tanks, flat rate. So, unless your tanks are near empty, a Nitrox top is generally cheaper than an air fill. For example, if my double 112 are half full (or is it half empty - either way that's fairly common after a typical cave dive), getting them topped with nitrox would be 112*0.08=$8.96, while getting them filled with air would be $14.
Ethan
[/quote]

Unfortunately the savings in Nitrox fills won't cover the cost of gas for the drive....... ;D.
Selling fills by the cubic foot is something we've been asking about here (in Milw), and so far none of the LDS owners has done it......