EAN 32... because that is what is on tap and we don't need to keep track of a bunch of different EADs or use a computer to do it for us... very simple to keep track of things when you use the same gas for dives within its parameter.
You're diving Nitrox: Do you choose best mix or standard mix
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Spectre
Contributor
Some other factors to think about is time. If they bank 32% then they might give you 'night before' requirements for anything custom, and might charge you extra as well.
Keep in mind that they shoot for 'within a percent', and I've found that to be the case more often than not, and the percent is on the high side [since the gas monkey can't fill a tank]. I once dropped tanks off asking for 30%, and ended up with 33.1%. I ended up having to fix it myself on my way out of town.
Keep in mind that they shoot for 'within a percent', and I've found that to be the case more often than not, and the percent is on the high side [since the gas monkey can't fill a tank]. I once dropped tanks off asking for 30%, and ended up with 33.1%. I ended up having to fix it myself on my way out of town.
Most of the time I will fill one set of tanks with 30% and one with 32%. The idea being that the 30% one is for my original 110' dive, and the second is for my intended second dive, which is anywhere between 80-100'.
If I wind up unable to do the 110'er, then I will typically burn the higher FO2 mix on the first dive since that's where the lower residual nitrogen amount is most important.
There are days where I know I won't be over 90'; for those I may make up some 36%, especially if I'm going to be doing 3 in a day.
If I wind up unable to do the 110'er, then I will typically burn the higher FO2 mix on the first dive since that's where the lower residual nitrogen amount is most important.
There are days where I know I won't be over 90'; for those I may make up some 36%, especially if I'm going to be doing 3 in a day.
Lemonade
Guest
Why not 32%? According to PADI guidelines, which are, I believe, somewhat conservative, MOD for EAN32 is 111'.
Ziggys_Friend
Guest
Okay, I just came home from a DIR/F course and they'd say EAN32. Why? Among other things, Keep It Simple ... in 0-100 foot diving the differences between EAN32 and EAN36 or any other custom mix are not worth the hassle and possible confusion factor. For example, figuring your EAD in your head and is a breeze with EAN32 (okay, it's not that hard with EAN36 either), but why add confusion. You can also throw those stupid Nitrox charts away. At 0-70 feet there is barely a difference and if you're going to dive over 100' you should be diving Triox (helium added) instead. Also, mixing EAN32 is simple.
~<//><
Mixing any mix is just as simple. However I have come to appreciate the benefits of using the same mix whenever possible. It isn't a big deal within the "no deco" limits above 100 ft but you really learn to appreciate the simplification when doing more complicated dives. It's possible to simplify dive planning to the point where it's a real art form and using the same gas is a start.
What does make mixing simpler is that if you bank 32% (or whatever) you then use trimix blends that are designed to mix by topping the He with that nitrox blend. Take a look at the gasses recommended by GUE and see how they work.
jbm,
Best mix is not in the PADI text. Study the rest and pick up best mix in 5 minutes after getting the IANTD text.
Best mix is not in the PADI text. Study the rest and pick up best mix in 5 minutes after getting the IANTD text.
Best mix is simply knowing depth and the deired PO2 and figuring out what mix gives it to you.
(depth/33 +1) FO2 = PO2 This is in the PADI text
Simply set PO2 to whatever you want (1.4?), fill in the depth and solve for FO2. No big deal
desired PO2/(depth/33 + 1) = FO2
Then see if you can buy it and if you can buy it see if it really gets you anything.
(depth/33 +1) FO2 = PO2 This is in the PADI text
Simply set PO2 to whatever you want (1.4?), fill in the depth and solve for FO2. No big deal
desired PO2/(depth/33 + 1) = FO2
Then see if you can buy it and if you can buy it see if it really gets you anything.
Because I want a slightly lower PO2 at 110' than the 32% gives me since we are usually spearfishing and that can get kinda hairy.
I rarely run into NDL trouble on these dives anyway, and the extra couple of minutes is not worth it on a trade-off perceptive with the O2 tox risk.
I rarely run into NDL trouble on these dives anyway, and the extra couple of minutes is not worth it on a trade-off perceptive with the O2 tox risk.
In VB we usually dive 32% and in NC 30%. NC stuff is a little deeper and due to the ever changing weather, you never know where you will really end up...will it be 120'-130' or will it be 70'..who knows..
Most of the shops down there bank 30%. We stick to 32% up here for the same flexibility.
Most of the shops down there bank 30%. We stick to 32% up here for the same flexibility.
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