First Nitrox Dives

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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.
 
Crowley:
After a number of years working in the industry I have come to the conclusion that those who do feel the benefit after diving on enriched air are often reasonably inexperienced and are suffering from (very) mild symptoms of decompression sickness (fatigue) due to poor buoyancy control, poor dive profiles or over-exertion on a dive when they are using air - all perfectly normal issues for a relatively inexperienced diver. Using Nitrox obviously eliminates their nitrogen uptake/release due to these factors and therefore their symptoms are lessened - ie, they are less fatigued. I think as time goes by, the effect becomes less and less because the divers's buoyancy and breath control become better.
Your comments match my personal observations.

Early on in my diving, nitrox gave me the extra margin needed to lessen post dive fatigue. I definitely saw a difference in post dive fatigue when repeating the same dive (multilevel repetitive dives pushing air NDLs) on air and on EAN32.

Then I improved my profiles, and IMO most importantly started to do deep stops and longer total ascent time. This eliminated fatigue whether on air or nitrox.

Charlie Allen
 
tridacna:
Harris RJ, Doolette DJ, Wilkinson DC, Williams DJ. Measurement of fatigue following 18msw dry chamber dives breathing air or enriched air nitrox. Undersea Hyperb Med 2003;30(4):285-91

Hmmm...so there is evidence. Results show no differences in fatigue perception after diving nitrox. You can let your buddies drive! :blinking:
The bottom time for these 18m/60' dives was only 40 minutes. This 40 minutes of bottom time include the 8 to 10 minutes that it took to reach 60'. The ascent than took 15 minutes. Very, very mild exposure.

IMO a much better test would have been to the more commonly accepted NDL limits of around 55 or 60 minutes at 60'. A common procedure in decompression trials is to signficantly exceed limits in order to increase the probability of DCS in order to get more meaningful data points from a limited number of tests, and in keeping with this sort of test design it would have been reasonable to have 18m/60' bottom times of even longer than 60 minutes. This is particularly important when such a small scale test (only 11 divers, 22 dives total.)

IMO the 40 minute bottom times make these trials nearly useless.

If you aren't stressing the body, then you won't see the difference.
 
Also, a sample of eleven divers is not sufficient for reliable results.

Like pretty much every area of diving, the effects of nitrox have little reliable scientific research behind the theory.
 
DandyDon:
:lol:​

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.

Hehe, check out my original Nitrox card....
Nitroxcard.jpg
Nowhere does it say anything about what kind of card it is, not on the front either. I used it many times before I got my combo Rescue-Enhanced Air card, no one ever noticed. They pretend to look. Diving Air, they usually don't check my card if I'm wearing an old T-shirt.

I think I'll stencil this one myself: DandyDiver-VoodooGas
bananawaves.gif




Had to give you proper credit Don!!!! :D :bananalama: Um nice avatar!!

Cool Card. I was wondering the other day if they offer a card with all of the certs that a charter etc. would ask for?
 
letsgodiving:
Also, a sample of eleven divers is not sufficient for reliable results.

Like pretty much every area of diving, the effects of nitrox have little reliable scientific research behind the theory.

1. Please justify your conclusions. I look forward to your critique of why the sample size was insufficient. Please base your reasoning on probabilities used in the study.

2. "Pretty much every area of diving" - Once again, what are you talking about? Check the DAN research files. There is a huge amount of data on exactly this. Ditto for the USN.

Have you actually done any research or are you just showboating?
 
If you "feel" like you aren't tired after diving nitrox, good. Then that's your perception or your reality. However you want to word it.

Placebos do work, you know?
 
https://www.shearwater.com/products/perdix-ai/

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