why nitrox

[The Iceni]

unit240 once bubbled...
I am looking to go on and take the deep, wreck and cavern courses all next year. . . Will the nitrox help at all?

Nitrox has many, many advantages but it is NOT a deep diving gas and supect for you, unit240, that Trimix is a long, long time in the future.

I agree with Landlocked. When you are on a boat with Nitrox divers and those diving air, make a mental note of the condition of the air divers. In my expereince they tend to be much more fatigued, the conversation and jokes coming from the Nitrox divers who it seems remain alert and always really enjoy themselves.

I blend my own tanks, aiming to give me a safe bottom mix providing a pp O2 of 1.4 bar.

 

[GP]

WreckWriter once bubbled...


Yep, trimix is even better. If cost is a concern, stay far away from there. Depending on your mix, $50-90 to fill a set of doubles.

Tom

Yeah, tech diving ain't cheap is it.

 

[The Iceni]

landlocked once bubbled...
Commonly, I will dive Nitrox on the first dive and air after that.

I am not having a snipe, landlocked but isn't this similar to reverse profile?

For the same depth, Nitrox has a lower pp N2 than air so is it not equivalent to a shallower dive with respect to decompression requirements?

Consequently, I tend to use richer Nitrox mixes for subsequent shallower dives, not air.

Can you explain your reasoning, please?

 

[DivingDoc]

landlocked once bubbled...
This old man just feels a lot better after diving nitrox as oppossed to air. After a long dive on air I feel tired and lethargic. I have always felt good after a Nitrox dive (usually around 32%.) Commonly, I will dive Nitrox on the first dive and air after that. Our LDS is reasonalbe in their prices.

Was recently in Coz for a week of diving. The second day, we did our 2 Nitrox certification dives, having taken the lecture part before we left. After that, we dove nothing but Nitrox the whole rest of the trip. We felt so much better after Nitrox than after air -- invigorated, even.

Of course all the advantages previously mentioned are good too.

ET

 

[Scubaroo]

Dr Paul Thomas once bubbled...
I am not having a snipe, landlocked but isn't this similar to reverse profile?

I thought reverse profiles had been reviewed and found to be inconsequential... does anyone have any references to confirm this?

 

[The Iceni]

bengiddins once bubbled...
I thought reverse profiles had been reviewed and found to be inconsequential... does anyone have any references to confirm this?

Hi Bengiddins,

The thread you alude to is located at

http://www.scubaboard.com/t11743/s.html

I agree that reversed profile in recreational diving is perfectly safe, because dive computes calculate deco needs on a minute by minute basis. The downside is that the decompression requirements are greater when the shallower of two dives is done first for typical recreational diving. The same applies to the END of a Nitrox mix, because it is the partial pressure of nitrogen that is the determining factor for decompression and it is less at any given depth for any enriched air Nitrox mix than air. This is also the basis of accelerated decompression with rich mixes such as 50% Nitrox and even pure oxygen (from 6 meters).

On the thread I tested out two theroretical dives;

The total decompression penalty for the reversed profile is 117 minutes, compared with 92 minutes with a standard profile, an additional deco penalty of 27%. However, probably more importantly the residual gas load in the slower compartments is higher (51% compared to 49% in compartment 16).

In summary, as I see it, reversed profile diving not only attracts added deco penalties, it leaves an appreciably greater residual inert gas load in ALL the slower compartments.

Thus is WreckWriter used his air for the first dive and THEN dived Nitrox his deco requirements would be far less. I am not at all sure why he uses air unless, of course, he is approaching toxic limiits.

In any case I still believe he should use his air first.

Does that explain my thinking?

 

[Scuba]

Is there any conclusive evidence to support the claim that Nitrox reduces the incidence of DCS?

Is the feel good affect discribed by some nitrox users the result of a euophoria produced by the mix as opposed to the result of less stress on the body?

Does breathing air with a higher oxygen concentration then that naturally occuring in the atmosphere have any short or long term affects on the body? Just curious.

Peter

 

[The Iceni]

Scuba once bubbled...
Is there any conclusive evidence to support the claim that Nitrox reduces the incidence of DCS?

Lots! there are even separate tables for Nitrox diving

Is the feel good affect discribed by some nitrox users the result of a euophoria produced by the mix as opposed to the result of less stress on the body?

Quite possibly, Scuba, as oxygen is a stimulant. Take a look at

http://www.scubaboard.com/t4425/s.html

Does breathing air with a higher oxygen concentration than that naturally occuring in the atmosphere have any short or long term affects on the body?

Peter

Yes acute CNS toxicity and accumulated whole body or pulmonary toxicity.

Sorry to be so brief Scuba but the Dr Deco part of this forum is stacked full of discussions on these very points.

 

[voidware]

Unless it is positively unavailable, I dive Nitrox. There is absolutely no reason to be diving air. Besides for my HP120, air is $5 and Nitrox is $8, and I can get two good dives off that tank.

Nitrox is 36% better than air.

brandon

 

[CincyBengalsFan]

You won't go wrong with Nitrox. Were doing a Nitrox class downtown town with the Bluegrass Divers Club for $125.00. Not a bad deal. I think Nitrox fills in Lexington are $12.00...I think...