Surface oxygen to reduce flight times

[WJH]

You guys must all live w/in driving distance of FL. You've never driven home from your last dive (at least in the passenger seat) with a mask on, breathing off your O2 bottle or at least your nitrox bottle? Why skip Little River as your last dive just cuz you fly home the next day?

Reports I have received of DCS and/or Chambers are not at all pleasant. I can come back and dive the sites again on my next trip. Or not. I like being unhurt.

WJH

[Scott]

You've never driven home from your last dive (at least in the passenger seat) with a mask on, breathing off your O2 bottle or at least your nitrox bottle?

Ive done it, but it was due to pain in my elbow after a 300'+ dive, not to shorten no-fly times.

Got a lot of weird looks from other drivers!


Scott

[DA Aquamaster]

The US Navy required a 48 hour surface interval prior to flight, but that was based on the possibility of explosive depressurization in a high altitude aircraft and/or very rapid climb rates.

On the other hand, when prepping for a high altitude flight in a pressure suit where you may be on 100% O2 but at a suit or cabin pressure of only 3 to 5 psi, you needed to bre-breathe O2 for a minimum of 3 hours prior to flight to "offgas" the nitrogen you normally have at sea level pressure (about 14.7 psi.) even without making a dive in the last 48 hours.

So...on one hand you have a very conservative approach to surface intervals based on a possible "worst case" flight scenario and on the other you have *only* 3 hours of pre-breathing being considered adequate prior to launch in circumstances that are very demanding in terms of possible DCI.

My mostly thinking out loud thoughts are that a flight in the average air liner (no more than an 8,000' cabin altitude) after 3 hours of pre-breathing O2 would be a total non problem, even if your surface interval were only a half day or so. Of course, I also want to see a diver trying to get through TSA security with an O2 bottle - lotsa luck - so best case you pre-breathe for a few hours on the way to the airport then figure out what to do with the bottle, then have a couple hours before flight breathing normal air in the normal every day fashion.

I think it would work fine, accellerated deco and offgassing being what it is, but I'd love to see some research on the whole thing before I actually tried it.

[bubbles]

You are much better off, even on a "no deco dive", spending time at 15 -20 ft on 100% oxygen than you are breathing oxygen on the surface. While breathing oxygen under pressure, you will offgas more rapidly than you ever would on the surface. This is why the hyperbaric chambers work! I wouldn't ever recommend shorting your no fly time. If you happen to be a "low bubbler" individual, you can probably get away with it...but if you're not, you may end up in a chamber. It all depends upon "how lucky are you" today. Having been in a chamber for a lymphatic edema hit, I can't say I can recommend the experience. I also would NOT want to experience DCS in a plane. IMHO.

[Squirrel Girl]

Because I really, REALLY don't want to know what DCS on a trans-atlantic flight is like...

No lie! I wouldn't risk it that way, either! And, believe it or not, I am *not* advocating reckless diving behavior. I do think that if it's >16 hours from your last dive, but not 24, you might consider breathing the gas, as long as you've got it conveniently available.

I don't recommend cutting corners in general. In fact I often run a more conservative safety factor on my computer relative to my buddies'. But depending on the circumstances, O2/nitrox in the car might be an option--and yes, I have done it. It was that LR dive, and I turned the dive before thirds to avoid added N2.

FWIW, I was a guinea squirrel at Duke for experiments in the chamber using O2 to shorten surface intervals.

[JS1scuba]

A long time used method of "raising your ceiling" after the dive is post dive oxygen breathing. It helps accellerate how fast you can fly or move to altitude. Specwar did some work with this, as have the US Air Force. Out on the west coast I started doing it a few years back when driving from California back to Arizona there is a high mountain ridge i need to pass over. Cajon Pass is just under 4000 foot elevation, another pass on farther down south is about 6k.

Take a typical 100 fsw dive for 75 minutes using EAN 32. Post dive you would need a surface interval of 12 hours before being able to ascend to 5000 foot elevation (NOAA Diving Manual 4th Edition Surface interval table 4.3) However if you run that same model and then put in 30 minutes of post dive oxygen breathing you push that time back to 20 minutes (pretty slick) You can also add 15 minutes of oxygen at 20 fsw (after deco is complete) and get the same results.

By displacing the residual nitrogen you gain the ability to ascend.

Cheers
JDS

[Randy Thornton]

I do it all the time when driving back to Salt Lake City from Lake Mead. I need to go over some 6000+ foot mountain ranges and having only been out of the water 4-5 hours, I always do it while breathing O2. It's worked every time so far for me, but I am not advocating it for anyone else!

[AB8CD]

What I want to know is how does Squirrel Girl get those cool holiday graphics?!!!

[adam0321]

I have done the whole driving on o2 thing going back to panama city before. I have also "volunteered" to jump in the chamber as another tender during treatments or practice runs after some long dives... I have also been in a haps (high alltitude) chamber before and the next day had the inside tender of the haps chamber in our chambers at the dive school for aviation bends. computers are great tables are good but there are so many factors and everyone is so different. I wouldent risk it because a plane is so limited as to what they can do.