First Nitrox Dives

[1_T_Submariner]

Codswallop.

1. There is no such thing as "nitorgen".

2. I would LOSE not "loose" my bet. I never tightened it. Nor did I make one. I was simply shoving my push...

3. You (not me) imply that it is the %O2 in the breathing mix that contributes to post-dive fatigue syndrome. I would further posit that we all know that Helium makes you talk in a higher pitch. It is this squeakiness that creates the feeling of well-being based on the Buehlwoman Donald Duck Syndrome (BDDS). Furthermore an analysis of the flatulence induced by the BS component of your argument could lead to sense of euphoria, clearly a marker for improved concentration and driving skills. I concede this argument to you. Brilliant logic.

I almost for a brief moment thought this was a serious post. Too funny.

 

[Hoffa]

As an experiment, try adding deep stops to your ascent profile next time around. You don't need to do anything fancy. What works for me is 1 minute at 40', 2 minutes around 30' or so, and then a normal safety stop. As I posted earlier in this thread, I found the either deep stops or going to nitrox cured my fatigue problem.

Charlie Allen

Thanks for the tip, Charlie! We'll try that.

 

[tridacna]

With such a subjective complaint (we don't have a fatigue-0-meter), it strikes me that it would be VERY hard for researchers to control enough variables to make for a good study.

Actually they do have objective ways of testing fatigue. See the original study. Fatigue can be tested in a number of ways. It's the "good feeling" that's hard to quantify. I DO know that after inhaling Nitrous Oxide at the dentist, I feel good. There's an idea brewing here. Wait, maybe that's what Th. was referring to!

 

[nereas]

Ok so I waited a while to take Nitrox. Good class though. Dandy Don talked me into it cause he said he doesn't like to dive with Air divers in fla. Maybe we will meet someday.

Yesterday I did 2 nitrox dives. On EAN36 one 60 minute with a drop to 80 feet (47 degrees F) then most of the dive at 50 feet ending with 20 minutes at 15-20 feet (Above 75 degrees F). 1 hour SI. The next dive was to 55 feet then up to 15-25 for 35 minutes Total time was 80 minutes.

I didin't feel any different (I.E tired etc..) after the dives. I did like that my computers NDL was alway a lot higher than on Air.
Anyway good course to take.

The main advantage of nitrox is felt on live-aboards when you do up to 5 dives in a day.

And the NDL graph allowing you to visualize the nitrox benefit for your diving is a good illustration of the added safety that nitrox gives you. Nitrox is truely the best mix for diving in the range of 50 to 100 ft.

I really like EAN36 as well, because you maximize those benefits, compared with EAN32.

When I was in Florida, the Florida-divers on the boat were using nitrox, by the way, and the Florida-boat-captain was encouraging its use. And the only divers on our boat who did not want nitrox were from Texas or Illinois. The Illinois divers were new to diving, but the Texans were experienced, and should have known better.

 

[nereas]

There's sufficient anecdotal data to make extending Harris, et.al.'s conclusions outside of their data set questionable. For example: when we used to go out on a cruise and dive air, after the first day or so you could always find the divers ... they were in their bunks. On cruises were we used NITROX that was not the case and many people commented on it. One way of testing the air/Nitrox fatigue factor qustion would be just to record how much time the divers spent in bed on different cruises.

I agree with the anecdotal findings.

Anecdotal simply means someone tried something themselves and they liked it.

The classical statistical argument against anecdotal findings is that such data are statistically insignificant compared overall with the entire universe of relevant information.

Still, anecdotal works for me. I suppose that I respect it more, because for technical applications, you are supposed to take everything slowly, and develop your own profiles gradually. This is surely anecdotal, and it works.

I do not know any techdiver who has ever done a 300 fsw dive on their first try. They normally always build up to it, with shallower, shorter dives first.

It is not about placeboes.

 

[nereas]

Ditto here.

I dive on Nitrox tables if everyone is on the same Nitrox mix, but most of the time at least one other diver dives on air - which leaves me diving air profiles instead.

I don't notice any change after only one dive, but on repetitive dives it makes a difference. How can it not? You do absorb less nitrogen. I doubt this positive effect on fatigue could ever be scientifically measurable with enough accuracy to be proven beyond any doubt.

Not only this, but you also dissolve more O2 into your blood plasma, due to the higher ppO2 (partial pressure). I suspect that the energization factor has more to do with the dissolved O2 than the lower amount of N2. But who knows? It could be due to both.

I do feel the rush afterwards. It makes me feel like Superman. For an old man, like me, this is a very good thing!

 

[nereas]

http://breathing.com/oxy-water.htm

I guess we could just use this stuff and extend our bottom times too.

You know that a multivariate analysis incorporating all of the variables you mentioned could never be performed. It's too expensive unless it was sponsored by the Society of Nitrox Divers (SNIDE) or Rodales (if they were paid enough). There has never been anything published (nor will there be) showing Febrile Improvement Bouyancy Statistics (FIBS) indicating post-diving improved fatigue (SPIF) correlation based on nitrox use.

Let's face it, if you feel better - great. But please no assumptions about the elevated O2 content of your mix causing you to feel better. It's purely subjective.

This kind of logic cuts both ways, of course. You can neither formally prove nor disprove anything, in this case.

 

[nereas]

I'll tell you who does. There are a whole bunch of LDSs that convince people that the reason that they should use nitrox is because of the "feel good" thing. I've heard and seen it often. That's crap.

I dive nitrox whenver I can. It's great. For feeling good after diving? Spend a few days a week in the gym exercising and you'll feel much better before, during and after diving!

I suspect a note of paranoia here of scuba stores.

One of the few intelligent things that some scuba stores do is to encourage nitrox, in my opinion. The rest of the trinkets and toys they sell may indeed be crap, but nitrox in my opinion and experience is a good thing.

It actually bothers me when new or small stores do not offer nitrox, and then try to argue that diving with air in the range of 50 to 100 feet is totally safe, and that there is really no need for nitrox. In this case the self-interest is quite obvious.

 

[nereas]

...

I don't like to dive deeper, like on FL wrecks, when I'm on Nitrox and the buddy is on Air. For Cozumel and other sloping reef dives, and on shallow dive, I dive Air - unless there is a discount package for the trip, or I do 3 or more dives in a day. And it certainly can help when the whole boat is on Nitrox, but this rarely works out for me.

...

Hmmm ... and you were the original inspiration for all this? Hmmm ... .

First, why do you care what your buddies are diving with? Why should that influence your mix choices?

For any given depth, there is always a best mix. You are either using it or you are not. And whether or not you are has nothing to do with your buddies.

Second, if you are diving nitrox and your buddy(ies) is(are) diving air, then the only major difference you should notice is that your surface interval will be more efficient, since your blood and your computer model is charged with less N2 loading. Ergo, you can then go back into the water sooner than they can, or else when you both go back into the water together, you will have a longer planned NDL time at the depth you both choose.

Third, its not like you are going to dive very deep, where you need to worry about FO2s (fractions of O2) controlling your depth. Most boats pump some variation on EAN 33 or 34, and that is safe down to at least 100 ft. (Lets not get started on the ppO2 debate over 1.6, 1.5, 1.4 etc.)

Forth, I find it puzzling when some folks use price considerations to determine their diving, such as for the cost of nitrox or of helium. It is such a small thing to use the ideal nitrox (or helium) mixes, and the down side would be $XX,XXXs of dollars/Euros spent on a hyperbaric chamber ride.

 

[nereas]

I was. I was at 5000 ft on a single tank of Nitrox. I saw my first deep sea vent. The worms were incredible. Suddenly I had a sharp feeling of pain in my arm and chest. I sucked hard on the reg to get more precious nitrox. (I was diving 65%). Instantly I relaxed and felt much better. (I'm not even over 50). My cardiologist said that without Nitrox, I was a goner. And after the dive, I drove home because my buddies (who had been diving air) were exhausted.

You were at 5000 ft? Was this in a submersible?

And your buddies were diving air at 5000 ft?

Hmmm. I thought that at a ppO2 of 3 there is virtually instantaneous convulsion. Did that affect any of you guys?

How does 65% nitrox work at 5000 feet? I'm curious.