Why do you use nitrox ?

[Thalassamania]

It requires proof. To take it directly from physics involves a complete lack of understanding of biological principles. Just because there is a theoretical reduction in something doesnt mean that by the time its been through a biology system it turns into a real world benefit.

It completely ignores things like thresholds for starters. There are many many examples of things that have on-paper theoretical benefits but absolutely no statistically significant proof of a real world effect. Many of these involve biological systems.

We have the theoretical underpinnings of classical physics combined with over three decades of operational experience, that is quite sufficient. Were it not, all those folks who use EAN to lengthen their underwater excursions would have been bent, and they were not. That demonstrates that a lower ppN2 exposure results in a lower nitrogen load. Granted that it is an extension to decide to take that "safety" on the end of decreased DCS risk, rather than for increased bottom time, but that's a well known and accepted trade, you don't have to agree, but the science stands in opposition to your idiosyncratic view.

 

[ScubaFeenD]

Most agencies teach O2 is at LEAST as narcotic as nitrogen and nitrox does not/should be used to reduce narcosis.

Sure, O2 is just as narcing, but it is complicated by the fact that the body actually uses O2 where as N2 that you take in is essentially "inert." O2 is imperfect, and I have never been taught that nitrox decreases the incidence of narcing. I do have anecdotal evidence that me and a few friends perform complex cognitive tasks better at depth--we work better under pressure

It requires proof. To take it directly from physics involves a complete lack of understanding of biological principles. Just because there is a theoretical reduction in something doesnt mean that by the time its been through a biology system it turns into a real world benefit.

It completely ignores things like thresholds for starters. There are many many examples of things that have on-paper theoretical benefits but absolutely no statistically significant proof of a real world effect. Many of these involve biological systems.

All physiologic systems follow the laws of physics. If physical laws dictate a situation the body must adhere to that law. Whether our models are accurate, and whether specific predictions and hypotheses are appropriate to describe phenomena, is a matter of experimentation. I think that the static (and actually decreased leves of DCS and injury in nitrox divers) proves much of what we believe to be happening with DCS and the like. We are involved in a huge experiment and it seems to be showing us that our predictions are right. Regardless, biology is a tricky bastard, and we rarely understand it perfectly--that is where application of physics becomes tricky. It is not due to some inherent biologic ability to evade physical laws.

-ddd

 

[GrumpyOldGuy]

Back to the OP's question:

I dive EAN locally since the dive is at altitude and 80' deep. It not only gives me longer bottom time on this profile (hr+ dives), but substantially reducing the SI needed which is really appreciated when the topside weather is crappy.

I don't bother on shallow shore dives. I am not close to NDL and I can enjoy the SI. On boat dives where a deeper profile is likely and I am trying to do 3 or 4 dives, it is worthwhile if only to give me a little extra margin of safety being old and fat. The cost is a small add-on compared to what I spend on a boat and transport to/from the site.

 

[carolsarinah]

Me too. I feel much better and can get as much as 4 long dives a day if I start early enough. I can not do that on gas for an entire week. I can on nitrox

 

[highdesert]

Our diving is all on extended vacation trips. We might do a 7-12 day liveaboard combined with 5-7 days at a resort. We logged 60 dives on our last trip. Since we travel a long distance to do this, and spend a lot of $$$ in the process, we want to do 4-5 dives every dive day (this is because we love doing it, not because we feel we have to get our $$$ worth). The issue is not increasing bottom time per dive, since dives all end up being somewhere around 65-75 minutes. It's the residual effect of nitrogen that starts to creep up, and Nitrox gives us a better safety margin and allows us to continue getting dives of that length for the duration of the trip. I personally don't think the "feel-good" factor is that significantly different with air or Nitrox after a week of long dive days.