driving to higher elevation after diving

[Thalassamania]

There is one interesting approach that's been overlooked.

I do not recommend it for recreational diving, but I will tell you that surface breathing pure 02 through a demand regulator for two hours will drop you from U.S. Navy Group N to Group A. I have used this technique when I had to make some serious dives and fly quickly there after.

Somewhere I have a table that provides specific repetitive group changes based on time and starting group (like a surface interval table) but based on pure oxygen rather than air.

Remember ... green gas is good gas (at least above about 30 feet).

 

[charlieo]

There is one interesting approach that's been overlooked.

I do not recommend it for recreational diving, but I will tell you that surface breathing pure 02 through a demand regulator for two hours will drop you from U.S. Navy Group N to Group A. I have used this technique when I had to make some serious dives and fly quickly there after.

Somewhere I have a table that provides specific repetitive group changes based on time and starting group (like a surface interval table) but based on pure oxygen rather than air.

Remember ... green gas is good gas (at least above about 30 feet).

I believe you are right. O2 will forgive a lot of your diving sins. When we dive Blue Hole, on the day we are returning to Denver, we plan all dives as if we were at 8000 ft. I like to do O2 for the 20 ft and 10 ft stops and/or safety stops. Longer is better with the O2. I try to avoid Rock Lake on the day of returning to Denver. "Try" but don't always do it. Then I do an early morning dive and O2 it and delay, have lunch, etc before Raton Pass. So far no bends.

 

[boulderjohn]

There is one interesting approach that's been overlooked.

I do not recommend it for recreational diving, but I will tell you that surface breathing pure 02 through a demand regulator for two hours will drop you from U.S. Navy Group N to Group A.

If you were diving nitrox, you could get a similar effect, probably impossible to calculate, by breathing your nitrox on the surface while preparing to travel--or while traveling. It would look a little silly to see someone driving along on the way to Raton Pass with a regulator in the mouth, but it would make a minor contribution to your margin of safety.

 

[Thalassamania]

If you were diving nitrox, you could get a similar effect, probably impossible to calculate, by breathing your nitrox on the surface while preparing to travel--or while traveling. It would look a little silly to see someone driving along on the way to Raton Pass with a regulator in the mouth, but it would make a minor contribution to your margin of safety.

The effect from NITROX is quite calculable but I suspect (without doing the work) insignificant. The point here is to maximize the diffusion gradient so that N2 moves out of the body as rapidly as possible, rather than simply slow the uptake of N2 by reducing its proportion in the mix.

It might look silly, but if that regultor was connected to a bottle of oxygen ... it might be quite sensible.

 

[fire_diver]

You have to remember that the dive tables were designed from a dive at sea level in mind. If you live at, and dive a sea level, then proceed up to 9000 feet, then you would be in trouble. If you live at 9000 ft, then you are starting out with a decreased nitrogen load from someone at sea level. As long as you stay within the NDLs, the atmospheric pressure change of roughly 4000 ft, shouldn't be a problem.

Of course, my reasoning could be flawed. It could be that you incur the same nitrogen load from an 80ft dive at 4500 as you would from an 80ft dive at sea level. Which would be why the altitude equivelency depth of the blue hole is over 100ft (if I remember correctly). Although, accounting for the END would still put you at an altitude change of only about 4500 ft to go home, which is still within the recomendations.

So now that I have have made this as clear as Oklahoma lake water for myself and probably for you too, I will go take some aspirin. Thinking hurts my tiny brain. Or else its just the effects of all the CO I suck up on my job.

FD