EAN32 usually.. When to use EAN36

[taymag]

I am fairly new and have always dove 30-70ft (other than in my AOW course) and have always just got EAN32, but I saw someone on my boat with EAN36 the other day. Possibly going to get yelled at for this but can someone just give me a quick rundown of when I would use EAN36 vs EAN32?

 

[djtimmy77]

I use 36 anytime I am diving shallower than its MOD

 

[kelemvor]

I usually calculate my best mix for a dive and have the shop blend what I need. If you are just using premixed nitrox then... assuming you're targeting a 1.4ppO2, 36% would be the ideal mix for 95' or shallower. For 82' or less you could do 40%.

Some divers i have talked to plan a 1.6ppO2 but that's more risky than I am willing to do.


The benefit to a more oxygen rich mix is less nitrogen absorption and therefore longer dive times. That is, if your dives are nitrogen limited and not gas consumption limited.

 

[ktomlinson]

The topic you want to search for is 'best mix'. Also, review 'max operating depth'. The last one is critical. If you have specific questions please ask. Hopefully you don't take this as yelling but the question you've asked indicates that a more in depth understanding of nitrox is needed to make sure you understand how to use it safely.

 

[djtimmy77]

All of these topics can be found in the book for your Nitrox class. Perhaps re-reading it is a good idea.

 

[fbk]

All of these topics can be found in the book for your Nitrox class. Perhaps re-reading it is a good idea.

Assuming they've done a Nitrox course in the first place...

 

[drrich2]

Perhaps the poster has noticed that EAN 32 is a very common banked mix, and EAN 36 much less so, and suspected the other diver might've had it custom blended, which might've involved higher cost. Since even the former gives pretty generous NDLs, and most boats aren't going over 2 dives and with some surface interval time between, he might've just wondered if there was some cost/benefit issue he was missing.

All speculation on my part, but I am Nitrox certified, I do get the basic difference, and if I were on a dive boat & glanced over and saw a fellow diver on a standard 2-tank recreational dive charter with a tank marked EAN 36, that's what would go through my mind in a moment of idle curiosity.

So, given his location is south Florida, is EAN 36 commonly banked at some dive shops in the region? If I were diving nitrox & it were the same price banked & immediately available, then I might go for it if I weren't exceeding the MOD.

Richard.

 

[boulderjohn]

Here is a shop in South Florida with banked EANx 32, 36, and 40, all for the same price.

Home - Go Dive Florida

 

[MB]

At the risk of introducing something to actually think about, if most of the dives are in the 30-70' range, why are we talking about 32%? Those dives call for 40%, not 36%. And 40% is not a foreign substance in SoFL.

 

[JahJahwarrior]

A lot of people just do the math to find the "max mix" for their depth based on a 1.4ppo2.

Don't forget to also take into account the CNS clock and OTU's, of course, but there's two other things to consider.

First, is exceeding your max depth. I don't like to use the "max mix" if there is a risk you can exceed the MOD. It's nice to know you are diving a mix that is pretty good, but lets you go a few feet deeper than planned and still be within 1.4ppo2.

Secondly, is mix confusion. You do have an analyzer at home, and analyze each tank before you use it, right? Even so, I like to keep standard mixes so there isn't a risk of skipping analyzing and diving a 36% tank when I thought it was a 32% tank. It's just another layer to prevent any issues, so two systems and processes should keep me from mixing up gases.

That said, one of the big reasons I use 32% for dives even when 36% could work is, I don't NEED 36% to do the dive, and I rarely get gas anywhere that doesn't sell 32% banked, so 36% would be a hassle to get.