Diving using Nitrox?

[Jim Lapenta]

I always said that after diving nitrox I feel better. Less tired, and am more ready to go the next day. When diving with alot of students it really helps. The ndl's are a bonus when assisting with two groups and doing as many as 8 dives in a day. Yeah they are short and shallow 25 min to 25-30 ft or so but they add up. The shorter surface intervals are nice as well. As far as using it for my own recreational stuff when just messing around I generally use air and if needed don't mind a bit of deco. SInce starting tech however I almost exclusively dive doubles (either 72's or 85's and pump em up to 3000 or so) and really have no worries as far as going OOA. I do have an al80 that I bought mainly for pool sessions and to use as a stage later on and at ow class depths 30-40 ft can easily get 1 1/2hours out of it. In fla on molasses reef I had a bottom time of 58 minutes started with 3000 and was back on the boat with 1400. As I generally don't play well with insta buddies I try to dive solo whenever the op lets me or will buddy up with someone who impresses me as competent with the understanding that I'm not cutting my time short if they are an air hog. I'll go back to the line with em but I'm not going up. I also am a firm believer in self sufficiency and once you get into the deeper levels of tech you start to realize that unless something happens early in the dive alot of times a "buddy" is the guy who watches the other go up for a chamber ride or notes the best place to start the recovery of the body. My feeling is it's best to adopt this mindset early on and focus on preventing a problem before it becomes one or learn how to save your own bacon. As a DM I do what is required of me. Diving for fun- I watch my back you watch yours if I can't handle a problem then help me or vice versa. I treat every dive as a solo. Nitrox is a tool that helps me manage it more effectively in some situations.

 

[MauiScubaSteve]

Gas management is not voodoo
...
The rule of thirds does not consider your buddy or your depth
...
I believe there is a very limited increase in risk over air
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At the very least, few actually ask questions about type and quantity of dives, usual average depth, instances of NDL or any other pertinent questions before spouting the various virtues of NITROX the Wonder Gas.

:voodoo: After your example earlier, your first statement makes me hopeful but confused, due the example earlier?...

:alien_2: My rule of thirds originated with my overhead training and takes into consideration which of the possibly increasing thirds is the important one to get me and my buddy out, often packing different cft's with different sac's as well as correcting for fitness, currents and stops. It can easily flex to the given recreational situation (including depth), but who would use it recreationally?...

:1book: Do you have data on EANx induced O-tox compared to undeserved DCI on air? I am interested in seeing it?...

But that last one?...

What!

only a fool would say that :guitarist

What!

For that questionable percentage of SB members and lurkers that would heed such ravings I would simply ask "why?"

Properly following the established procedures, nitrox will result in some benifit over the same profiles with air for every diver on pretty much every nitrox dive; either less nitrogen saturation or longer bottom time (sometimes both).

Whether it is cost effective or whether you have the discipline to keep yourself above the mod are questions the op might be able to decide, if we would get back to discussing his situation.
:focus:

 

[Meng_Tze]

....

The rule of thirds does not consider your buddy or your depth.... or even attempt to determine a specific number where ascent should begin, it only determines your turn around point and your reserve amount. Divers should be able to have a bit more certainty than that.

...

Seems there is a clear lack of understanding of gas management and -laws here. This is all about volume used. Volume used is related to depth, time and RMV. This rule of 3rd allows for diver and buddy to return to originating point should a total loss of gas happen with one diver at the furthest point from the originating point.........(re-read over and and over again. Then think it through if unsure what it means).

In open water it is very conservative if there are no hard requirements to return to originating point.

Not sure what you mean by 'or even attempt to determine a specific number where ascent should begin'. But if this means a pressure number, then may I suggest a translation from volume used to pressure in tank as all people using gas management planning should be able to do.

What am I missing in terms of needing more certainty?

 

[Leejnd]

I'm beginning to think that, as happens so often, we are dealing with a "troll" situation. One person tosses out posts that no right-thinking person would agree with, and watches the frenzy as we all rush to dispute and discredit him.

I think it would be pretty obvious at this point to any reasonably intelligent diver what the realities and facts are with Nitrox. As has already been explained (time and time again, in other threads as well), there are specific, distinct and measurable benefits to Nitrox in CERTAIN recreational diving situations. If a diver believes they may find themselves in those conditions, then they should take a Nitrox course. If not, then some may consider it a waste of money. I personally don't. Even if I only found very rare use for Nitrox, the class itself expanded my knowledge about diving, gas planning, and other topics. As far as I'm concerned, anything that I do that expands my dive-related knowledge is a good thing and not a waste of money.

With that in mind, I personally believe that any more anti-Nitrox posts would be superfluous and clearly indicative of a hidden anti-Nitrox agenda. (Although why someone would be so passionately against a gas is beyond me!)

 

[Nemrod]

Whether on Nitrox or air or whatever, the Rule of Thirds is flexible and as mentioned for open water is very conservative which is why most non-overhead divers may find it to confining. My answer is that if you cannot at least pay lip service to the concept of the Rule of Thirds by breaking your air supply into three components---the gas you dive out and down, the gas you save for return or ascent and the gas you save for emergency--three components, then you need a bigger tank or tanks to satisfy your dive requirements/plan. For simple open water dives those three components may not be exact 1/3s.

As to the Nitrox--ho hum, the benefits are one of those "proven" facts--lol.

N

 

[1_T_Submariner]

Maybe we should open this debate up to snorkeling

Untitled Document



Ok just a little humor, I found when looking at Bonaire Info.

 

[Twiddles]

First off, I dont enjoy being referred to as a Troll because I have a differing opinion of the value of Nitrox. I will assume I am not being baited for fun by those posting.

Halemano, DAN has the information you require as well as the slight increase of risk for DCI (granted it is assumed this increase is caused by diving out of MOD). It is none the less an increased risk. As to not asking the questions regarding actual need vs assumed benefit, regardless of the reason it doesnt benefit the diver.

Meng_Tze I understand how to [calculate] the required amount of gas needed to safely return my buddy and myself to the surface. So your remedial class on the rule of thirds is of little use to me. So when YOU use rule of thirds you sit on the boat calculate in your Sac your RMV, your buddies Sac and RMV, your planned depth and what depth you should be at as you return to the surface right? BS, its not how its used, its out till you hit x psi (having predetermined the psi, before you started) then return since your not taking into account safety stops (you didnt do those on the way out) or your actual return depth which may be deeper than your outbound path your hoping your "close" of course your already 3 minutes off but hey thats what the reserve is for right?? I dont need to do volume conversions with my buddy at depth, cause I PLANNED my dive.

Leejnd I am very glad to hear your Nitrox classes gave you a better understanding of gas planning, I am very sorry to hear the math was too hard for you. Im equally sorry for your buddy.

Nemrod my issue with thirds is not that it cant be used. Its that it leaves to many things to chance. Even using exact math, knowing your Sac rate and your buddies sac rate, calculating stops, and ascent times still leaves room for a lot of error (current, temperature, increased Sac due to stress, etc).

Finally, as you have all pointed out, there is absolutely no reason for me to be against Nitrox. None. Which is why I have not ever been against it. I am against misleading divers who go OOA (not literally) far more often than NDL. I am against not asking questions before touting its benefits. I am against telling people things that are flat out false (such as lower risk of O2 Tox) or you can dive deeper (not said here) or you "feel great" after diving Nitrox (subjective, and disproved in testing, but hey a placebo cures cancer so your mileage may vary).

 

[Jim Lapenta]

I'm with lee on this one. I'd also like to know how many people you have assisted with on their ow checkouts, pool sessions, and classroom sessions? Also what is the average SAC rate of the people you dive with that they are running out of air before hitting the NDL's? I also did not see where lee said the math was too hard for her. I don't feel sorry for her buddy at all. I feel sorry for the buddy of an AOW who has so much book knowledge that it must be shown while degrading another poster. Common courtesy and common sense would be much more desirable in a dive buddy or human being in general. My grandmother used to tell me that nobody likes a know-it-all, especially when they insist on showing it to the world. And as for things that are flat out false- how about the fact that regardless of something being disproved in testing many people swear that they feel better after using it on a dive. There is no baiting here either. Troll is not a term tossed loosely around on here. Maybe a change of avatar signature would be a step in the right direction as well. "Problem child" does not do much to dispel the troll idea.

 

[Twiddles]

Its strange you would say you disprove of my statement regarding Lees math skills but ignore the fact she called me a troll and then you lecture me on common courtesy as you infer that my avatar or slogan makes it okay to call me a troll....

She made the statement that she had a much better understanding of gas management following an earlier statement about the math in the gas management steps I posted being too difficult, I think my statement was fair, and considerably nicer than calling her a troll.

None of your questions have ANY bearing on the discussion at all.... since all of them are asking questions regarding ME assisting, checking, pool sessions, etc. You obvious browsed my post because I stated that the placebo affect could in fact cause you to feel "better" after using Nitrox but should not be stated as a benefit because it is subjective and disproved.

Here how about this; All divers COULD benefit from Nitrox, BUT, as a responsible instructor, dm, diver, forum poster, etc, I should ask some basic questions to determine whether or not it WILL benefit the diver asking the question??? Now whether I have a 1000 dives or 1 my experience means zip, cause you can ask for yourself . However since this has gone this far and I have said this same thing on page 3 of this post I suspect you have a reason for not asking (also stated earlier). Difference is Im willing to ask divers questions as opposed to assuming I know whats best for them (or just selling them on something because... well you know where thats going).

 

[Meng_Tze]

...

Meng_Tze I understand how to [calculate] the required amount of gas needed to safely return my buddy and myself to the surface. So your remedial class on the rule of thirds is of little use to me. So when YOU use rule of thirds you sit on the boat calculate in your Sac your RMV, your buddies Sac and RMV, your planned depth and what depth you should be at as you return to the surface right? BS, its not how its used, its out till you hit x psi (having predetermined the psi, before you started) then return since your not taking into account safety stops (you didnt do those on the way out) or your actual return depth which may be deeper than your outbound path your hoping your "close" of course your already 3 minutes off but hey thats what the reserve is for right?? I dont need to do volume conversions with my buddy at depth, cause I PLANNED my dive....

.

You are right Twiddles, unfortunately your response indicates to me that you have not read/understood my comments clearly. Maybe you do, but it is not coming out concisely..



I stand corrected in your presence on this. ....:no