Nitrox for shallow water artifact diving??

[calabash digger]

I was talking to a buddy about being so tired after chasing artifacts in shallow water and burning down two 133 s which last forever in shallow water...My dives are forty feet or less and most of the time 20 ft or less. He told me nitrox diving would help with the next day tiredness...What do you guys think??

 

[Marie13]

I definitely feel better after diving nitrox. I use it for all my diving. Shops around here bank 32%, which makes it easy to get, and most of my diving to this point has been above the MOD for 32%.

Try it out. Are you already nitrox certified?

 

[boulderjohn]

I don't think you will get a whole lot of benefit. If you are using up two 133s at that depth, there is a good reason you are tired. For me, it would depend upon the price of your nitrox. I can get it very cheaply, so I would use it, regardless of the fatigue issue. If I had to pay the price most shops charge, I would not use it.

 

[rick00001967]

my first question would be.....how long are these dives at 40 feet ? the NDL on the SSI table is 130 minutes. are you exceeding this ? or coming close ?

many will say nitrox helps with lethargy after diving. i cannot say i have ever noticed a difference when i have used 32%.

as was said above, if the cost of nitrox is low for you it certainly can't hurt.

i would make sure you are very well hydrated before the dives and be sure to replenish fluids immediately afterwards. i would suggest a sports drink. i like to use blue powerade. diving can be a lot more physical than some realize, especially being active for as long as you might be. breathing that nice dry air also doesn't help, so a lot of hydration is lost.

 

[boulderjohn]

my first question would be.....how long are these dives at 40 feet ? the NDL on the SSI table is 130 minutes. are you exceeding this ? or coming close ?

Good point. With shallow water diving, we often forget that DCS can become a factor because the NDL is so far beyond normal gas supplies. Subclinical DCS may be a factor, in which case the nitrox would absolutely help.

 

[johndiver999]

Nitrox serves to just "knock" a few feet off the "effective" depth of the dive relative to air. My first inclination would be to say it will make no difference. But then I decided to put some numbers on a spreadsheet.

If I am doing it right? Then using 36% at 30 feet is about like using air at 18 feet with respect to PP of nitrogen. So I guess the answer is yes it could reduce the "effective" depth a good bit. I think it might matter if you are diving closer to 40 than 20 feet from a practical matter.

Another thing to consider is the effects of the long term thermal stress associated with diving. Unless you are in very warm water, even if you are wearing adequate thermal protection, you are probably experiencing some significant heat loss after hours of submersion even if you don't feel really cold. One of the effects of a very gradual and slow cooling of the body is that it is not that noticeable or uncomfortable and your core temperature can get depressed a good bit without you feeling that cold. This does tire you out.

 

[MaxBottomtime]

Artifact collecting involves lots of swimming, digging around, and carrying items around in a bag. Doing that for a few hours will get anyone tired no matter what gas they are breathing. Oh, and there is no empirical evidence that nitrox makes you "feel" better.

 

[AfterDark]

OP posted 40FSW or less; with that in mind any dive above 33FSW there are no NDLs so nitrox would be no help. Above 33FSW the whole dive is a SS.

 

[johndiver999]

OP posted 40FSW or less; with that in mind any dive above 33FSW there are no NDLs so nitrox would be no help. Above 33FSW the whole dive is a SS.

It is true that there is theoretically no limit for dives to 33 feet or less, but that does NOT mean there is zero decompression stress from the dive(s). Nitrox will most definitely reduce the nitrogen absorption and degree of supersaturation experienced by the diver. The question is: is it significant enough to matter?

For example, my little spreadsheet says diving 36% at 40 is equivalent to air at about 26 feet.

 

[calabash digger]

2 years of artifact hunting and only one dark water dive in the 40 ft range, 5 or 6 in the 35 ft range, and the others have been 25 ft or less. Thanks for all the info.. Was asking because I was gonna look into getting Nitrox cert if it was gonna be worth it. I will check the price of fills... BTW I really like this site lot of experience here!