Turtlebait

My buddy John and I (yes we're still friends) were discussing the pros and cons of Nitrox diving over compressed air. We bought the NAUI Nitrox workbook and after reading it, we were still undecided about it.

With compressed air you can go to 190ft with only being "narc'd" and having to make decompression stops in a worst case scenario. A diver recently went to the sand at the "O" on air, something Nitrox would not allow, with no unforseen effects.

Nitrox, with its higher O2 content, "draws" a line in the water column which youMUST NOT pass under penalty of Hypoxia, which could lead to convulsions and/or DEATH! That's a hell of a penalty to pay if for instance a cobia or amberjack drags you past your planned depth.

According to NAUI, the safe ppo should not be greater than 1.4ata. But of course with all the different physiologies and environmental concerns the individual diver brings into the equation, you may still experience hypoxia.

If any of you have read my dive stories, youknow how things can go south pretty quick. A penalty of "convulsions and/or death", is in my mind, too high a price to pay if things don't go according to plan.

If any of you Nitrox divers have found violating the "line in the water column" is not a big deal, please give me some insight.

Clay-Doh

I probably should not say this, bUT...yes, that "line" should not be crossed. However, it is a line with 2 variables, your po2, PLUS the amopunt of time spent at that.

Sooo....in an emergency? A brief minute will not cause the symptoms under most cases, in fact, you will feel less narcosis due to the less nitrogen in the mix (maybe? just a thought).

That being said, I am not recomending thinking of that line as a line to be crossed if you see that big fish just a little deeper, ect. I am saying that the effects are not insantaneous, therefore in an emergency,...well...you get it.

Look at the po2 people are under for controlled amounts of time in medical situations.

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lobsterman

Here it is in a nut shell. I have been diving nitrox since 92 and wouldn't go back, however I never dive in water deeper than 130'. If you are planning a dive in deeper water then just don't take nitrox with you. It is that simple. I absolutely feel 100% better after a dive with nitrox than with air, so for me the benefits far outweigh the negatives. In the mid to late 90's my buddy and I were diving 3 tanks a day 3 or 4 times a week. It to me is safer if you follow the guidelines. I also say if you are hanging in waterdeeper than 190' and suspended and shoot a cobia period you have rocks in your head. I have shot many cobia and have yet to put a kill shot on one. So that to me is suicide reguardless of the gas you are breathing.

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SCUBA Junkie

I'm with the previous poster, and I don't dive on "air" at all. Yes, there are some Nitrox specific risks, but there are just as many, or more, with breathing air, heli-ox, tri mix, etc....

I like it mainly for two factors; I feel better after a day of diving and I like the additional safety barrier against DCS (bends).

Yes, you do have to be more mindful of your PO2, but if you observe the recreational limit of 130', you will not exceed the prevailing limits. Oxygen toxicity is also a cumulative issue, not a solid wall, meaning you will not necessarily have any problems if you exceed your PO2 level for a short time, but if you continue to load high oxygen levels, you may experience those nasty neurological symptoms.

Safe SCUBA is all about knowing your abilities and limits, and staying within both.

I recommend doing as much research as you can on the subject before making your decision.

Turtlebait

Another issue I haven't gotten a clear picture of is the use of steel over aluminum tanks. Is there a reason the majority of Nitrox divers use steel, other than the higher volume and pressures they give?

Telum Pisces

The amount of benifits that you obtain by diving nitrox far outweighs the few limitations that it puts on you as far as depth. As with anything in diving, there are limitations.

If the sand is shallower than your maximum depth on nitrox and you follow all other guidlines, I see no reason to worry about air vs. nitrox. I feel so much better when I dive nitrox. Before I got my nitrox cert, I was getting sick:sick fairly often after about the second dive of the day on almost all trips. I have yet to get sick since diving nitrox.

Steel gives you more air as you said and allows you to drop weightdue to the buoyancy characteristics. Aluminum tanks become positive towards the end of your dive requiring you to carry more weight to begin with.

Sniper Spear-It

Nitrox is the way to go. do youre homework and you will find this to be true. most people dont have to worry about taking an o2 hit if they follow the parameters. i myself try to keep my po2 below a 1.6 but have often gone to 1.8. not recommending this just FYI.

as far as the steel vs the al. Steel is the way to go. you get to drop weight off of youre

belt and if you ever ask a commercial spearfisherman,the will only recommend steel. since those guys probably dive more than anyone else. i will take there opin.

SSI

seanmclemore

well i guess i'll give my $.02 since i was mentioned at the beginning of this post.

you guys/gals can keep arguing the pros/cons of nitrox vs air till the cows come home,

AIR IS NITROX

21% to be exact

all you are arguing is the safety factor and pushing the pp02 limits. one of the first thing you learn in training (or should be depending on who's teaching) is that you plan you mix based on you planned depth. now, as you advance in training and start to dumb things like touch the sand...you plan your mix for the max you could hit in a given situation...which at the "O" is a different situation because then everyone would be diving air.

anyhow, back to the point, when spearfishing something like the tennaco rig, most people will take a mix for 170' because likely they will not go to the bottom and dig a 10' hole and sit in it for an hour.

now draw your own preferences as to richer mixes, yes it makes you feel better after diving, yes it doesn't give the dry mouth, and yes if done properly IT IS SAFER

cheers

Corpsman

IMHO the two things any diver can do to make diving more enjoyable is A: Buy a computer and B: Get NITROX certified.

Turtlebait

After reading your comments and talking with a Nitrox instructor today, I signed myself up for the Jan 7 Nitrox class.

The main selling point was about feeling better after a dive - no headaces, no nausea,etc. I don't think I'll be getting a Nitrox computer just yet. I'll keep my air computer for a while, get used to the whole Nitrox scenario, then look for a computer that reflects my dive parameters.

Thanks to all who posted on this subject:clap I applaud your knowledge and understanding to a diver who was overwhelmed by the whole thing.

Again, my humble thanks:bowdown - Ric