Is it safe for me to fly? I really need to get home.

[clownfishsydney]

Still not sure what dives he did. Was it 45 minute long dives or 25 minutes? Very confusing. If it was 25 minutes, then not so bad. If 45 minutes and only 25 minute surface interval, then more problematic for a number of reasons. I always use 24 hours when on a trip but 12 hours if just one dive and not near NDL.

 

[johndiver999]

You people have no sense of adventure. Commercial flight is always an adventure, not knowing if you are going to smashed into your seat by a larger than life human sitting against you.

Why not add a little spice, and allow the traveler to also wonder if he will get a DVT or a little paralysis as well?

Hell the flights are so often delayed, he will probably have extra time to fizz, before the wheels are up anyway.

 

[L13]

Absolutely do not do this -- it will go to zero LONG before it's safe to fly. In the 2002 Duke study, GF99 was at or below 0 at the 3 hr mark, but at the commercial flight pressurization altitude of 8000 ft, it was 38%. More than 8% of the subjects in that group developed DCS.

I was actually referring to the percentage indicated in the Garmin Surface Interval app (since that is the computer I'm most familiar with). It's percentage is not GF99, but rather the % above "normal" ambient inert gas pressure. So 0% is 0.8 ATA (0.7 9ATA for the pedantic), 20% would be 0.96 ATA, and 10% would be 0.88 ATA. GF99 = 0% (tissue inert gas pressure = total ambient pressure) would be about 25% on the Garmin Surface Interval app. With 10% Garmin at the surface GF99 would be < 0%, and at 8000ft would be GF99~=19% (assuming the nitrogen peak is in tissue 6, typical for this kind of dive history). Which is essentially the same as the GF99~=18% at 8000 ft after an infinite stay at sea level due to tissue 16.

I forgot, that the Shearwater (and likely other computers) might indicate tissue saturations in GF% on the surface. Thanks for highlighting the difference.

 

[inquis]

Could you please link this study?

The proceedings of the 2002 DAN Flying After Diving workshop are available directly from DAN's publication library; but unfortunately, I cannot attach the entirety due to copyright issues. However, I feel an excerpt would fall under the "acceptable fair-use" criteria:

I calculated the GF99 values at an ambient pressure of 8000 ft to be: 142% (0 hr), 38% (3 hr), 26% (6 hr), 20% (9 hr), 18% (10 hr), 17% (11 hr), 16% (12 hr). For reference, the Navy table ascent time is 14.25 hrs (GF99 @ 8000 ft of 14%).

 

[inquis]

Which is essentially the same as the GF99~=18% at 8000 ft after an infinite stay at sea level due to tissue 16.

If your tissues are at equilibrium at sea level, your GF99 at 8000 ft would be about 1.3%, not 18%. Following the Navy ascent guideline for that Duke dive (60 fsw/55 min, wait 14+ hrs) would yield a 14% GF99 at 8k ft. I would not want to fly with an 18% value.

 

[Alekseolsen]

[Shearwater needs to add an @+10,000ft readout.]

OSTC has something like it. Uses GF settings but for "ascending" to 0.6 bars instead of 1 bar absolute.

 

[Capt Jim Wyatt]

You should go look up AGE.

You cannot suffer from AGE from flying after diving.

 

[BlueTrin]

[Shearwater needs to add an @+10,000ft readout.]

Do we know if you can apply the same rules for 10 000 ft? I.e. is there enough evidence?

 

[MidOH]

You people have no sense of adventure. Commercial flight is always an adventure, not knowing if you are going to smashed into your seat by a larger than life human sitting against you.

Why not add a little spice, and allow the traveler to also wonder if he will get a DVT or a little paralysis as well?

Hell the flights are so often delayed, he will probably have extra time to fizz, before the wheels are up anyway.

I'd rather pass out from DCS if I have to sit next to another fat Mexican lady again. She had no concept of folding her arms and elbowed me in the ribs for 2 hours.

 

[Joneill]

You cannot suffer from AGE from flying after diving.

What if they unknowingly have a PFO? Is it possible then?