Nitrox question

[pacificgal]

I could post this on the basic scuba forum, but would rather hear from those that are familiar with our local diving.
Convince me why I should get nitrox certified. Keep in mind I also want to be drysuit certified, rescue certified and take Essentials.
And if you tell me essentials could also get me nitrox certified, that would be a +1 in my book.

 

[Gombessa]

To start, you'll want nitrox if your dives, by virtue of time, depth or repetitive dives, are starting to be NDL-limited rather than gas-supply-limited. If you find yourself diving to 70ft for more than, say, 35 minutes, want to and have the gas to stay longer, but need to ascend because you're pushing against your table/computer limits, then nitrox will give you more time (20% more time, in the case of 32% nitrox). There are other reasons, but that's the big one. For many cold-water divers, it typically comes into play once they get into drysuits, as they find they can stay down much longer, and more comfortably, when they're dry/warm.

 

[Guy Alcala]

Nitrox question

I could post this on the basic scuba forum, but would rather hear from those that are familiar with our local diving.
Convince me why I should get nitrox certified. Keep in mind I also want to be drysuit certified, rescue certified and take Essentials.
And if you tell me essentials could also get me nitrox certified, that would be a +1 in my book.

To start, you'll want nitrox if your dives, by virtue of time, depth or repetitive dives, are starting to be NDL-limited rather than gas-supply-limited. If you find yourself diving to 70ft for more than, say, 35 minutes, want to and have the gas to stay longer, but need to ascend because you're pushing against your table/computer limits, then nitrox will give you more time (20% more time, in the case of 32% nitrox). There are other reasons, but that's the big one. For many cold-water divers, it typically comes into play once they get into drysuits, as they find they can stay down much longer, and more comfortably, when they're dry/warm.

What Kenn said. If you're shore diving anywhere but Lobos, Pt. Pinos or Monastery, you probably will run out of gas before you can reach a depth where your NDL is the limiting factor, unless you're using doubles or really big tanks. Boat diving is a different matter - for a site like Ball Buster Nitrox can make a difference. Personally, I never use it under 50 feet and generally not under 70, and deeper than 130 it really doesn't give you much advantage as you're using a relatively weak mix, < 28%, and your NDL is pretty limited in any case. I find 32% is most effective for me in the 80-110 foot range, 36% at or below 90 ft. Nitrox really comes into its own for multi-day liveaboard trips where you may be doing 4 or more dives a day. So, it's not essential for most of our recreational diving around here, but useful to have. And there's also the extra safety factor of diving Nitrox but using air NDLs, if you use it that way. I don't feel that the minimal extra safety provided is worth paying 50% more per fill, but that's me.

There's one more potential advantage to Nitrox, although whether it's psychosomatic or physiological is subject to endless debate (the scientific evidence is limited); Many people report that they don't feel as wiped out at the end of a day if they're using Nitrox as opposed to air.

AIUI, UTD Essentials does not include a Nitrox cert, GUE Fundies does (I'm sure Don will correct me if I'm wrong). So I'd get the other certs first, unless you find that you're regularly bumping up against your NDLs when you've got plenty of gas. Getting into a drysuit, once you get comfortable with it, may well be the trigger that drops your SAC enough to make it worthwhile.

Guy

 

[pacificgal]

Thanks for the info, Kenn and Guy.
I'm going to take EFR this month to get ready for rescue and hope to take Essentials in January (c'mon xmas bonus!)

 

[Anti-Hero]

"Nitrox has all but eliminated the need for air diving shallower than 100ft (30m) [snip] What this means is that air diving is becoming a curious historical footnote as divers continue to appreciate the advantages of proper mixtures." - GUE Tech 1 manual.

 

[mikeguerrero]

Kristina,

Nitrox really helped me out because when I was diving Point Lobos during the week I was running into a problem.

I would arrive at Lobos, get suited and be in the water at 9am. We would finish the dive come out and eat relax and off gas. Then on the second dive we would be in the water by 1pm and out by 2pm.

This was working for me because I needed to leave the park at 3pm to be back at work by 6pm. So if I started our first dive later than 9am, I was cutting my second dive shorter because I didn't get to off gas completely on regular air.

Simple solution? I started diving Nitrox, now even if I had the same quick surface interval I still got in a little longer margin of time to relax and enjoy the second dive.

It was the best thing for me, because I hated looking at my computer and seeing all those bars of Nitrogen still theoretically in my blood.

With the Nitrox the loading is less, so for mulitple dives it's a plus. I cannot complain on the price of Nitrox, because I get air fills for free anytime I want them and Nitrox is a fraction of a cost for me than other divers pay...

MG

 

[kathydee]

Kristina, Sounds like a great plan! I love taking SCUBA classes . Learning more skills makes diving that much easier & expands where you can safely go underwater! Oh yeah did I mention more skills = more FUN! I can't wait for my next class !

Another vote for Nitrox - I dive it on pretty much every dive.

Simply put - I'll echo the others: With Nitrox you can stay deeper for longer and/or have less nitrogen loading.

This is definitely a topic of debate, but I always feel much better after diving nitrox than air.

If you buy fill cards at Any Water Sports - diving Nitrox is pretty inexpensive.


One disadvantage? If your tanks are already full & you want to do a pool session, what a waste of Nitrox .

UTD Essentials does not include a Nitrox cert, GUE Fundies does

That is correct. But if you are nitrox certified, UTD will provide a 32% NDL table to calculate bottom time.

hope to take Essentials in January (c'mon xmas bonus!)

I bet you could talk Don into scheduling the next class date in January. Especially if you find another classmate or two !

 

[mikemill]

Less then 60 feet on a single tank I don't see a benefit vs the cost. 60 to 100 heck yeah use Nitrox if possible. Doing a week long diving vacation for sure. Doing two shore dives on the weekend, meh.

Part of my problem is that Dolphin does partial pressure blending so I'd have to get my tanks cleaned. And I'm pretty sure their safe air isn't $2/fill like the normal air.

 

[rdjiv]

It probably goes without saying for most here, but another thing to keep in mind when diving with nitrox are the O2 limits in addition to the no deco limits. Not much of a concern when sticking to moderate depth limits or single dives but does become something to track as you go deeper and/or over multiple repetitive dives.

 

[Peter_C]

Part of my problem is that Dolphin does partial pressure blending so I'd have to get my tanks cleaned. And I'm pretty sure their safe air isn't $2/fill like the normal air.

Dolphin was willing to fill doubles that were not O2 cleaned. They are not willing to do singles that do not have the proper vis sticker and a big ugly corrosion causing Nitrox tank band. They did not insist on O2 cleaned tanks. Jim would probably know for sure I believe they continues blend, through their fill station, off their banks?

Personally I dive nothing but 32% (Non deco diving). I do not want anything else in my tanks. That way I know my tanks are getting "E" grade air, and I do not have to worry about gas mixture, as it will always be around 32%. I have three O2 sensors available to compare readings against, so I know what I am getting consistently.

For me, diving Nitrox helps keep headaches at bay (No I am not a big skip breather). Seems no matter what I do I am tired after a day of diving. Although it probably does help diving enriched air. Improved bottom times, but that is a given.

I do not know about other dive shops, but Aquarius on Del Monte posts their air test result on the wall next to their fill station. I like to see the certs displayed.