Intersting that the NOAA website states;
'The cabin pressure in commercial aircraft is maintained at a constant value regardless of the actual altitude of the flight. Though cabin pressure varies somewhat with aircraft type the nominal value is 8,000 feet. For commercial flights, use a final altitude of 8000 feet to compute the required surface interval before flying.'
So they dont support the 24 no fly rule inposed by so many tour operators, just treat a flight as you would a 8000ft/2500m drive, which (I think!) means if you end your last dive in group C you can take off in 3 hours (practically impossible to do, 3 hours from end of dive to take off?) or 7 hours in group D, 24 hours would be group L! How many recreational divers ever end up in group L!
I almost posted this last night, but since this 8000' thing keeps popping up, I offer this nugget for thought and discussion... Although I know very little about the NOAA system, it seems they are assuming that approximately 8000' is the maximum pressure altitude you are going to be exposed to on a commercial flight in order to calculate their flying after diving restrictions.
Before you dismiss the 24 hour no-fly rule in favor of the NOAA standards or treat the flight as an 8000' drive as discussed above, consider what might happen to you if that jet depressurizes at a significantly higher altitude... I understand that the jet will immediately descend if able, and that oxygen masks will magically appear from nowhere, but that is not where the story ends...
There could be weather under you that prevents a descent. The jet might only descend to 10,000' or 15,000' and stay there for quite some time based on terrain, weather, airspace restrictions, and dozens of other things out of the scope of this thread. Most people can survive pretty well at those altitudes with only mild symptoms of hypoxia. I go offroading almost every weekend here in Colorado above 10,000'. I do not, however, go up there with residual nitrogen in my system from a recent dive.
The mere difference between 8,000' and 10,000' of pressure altitude (2000') already has people talking on this thread... If guys are worried about getting bent from ascending 2,000' after a dive, I would hate to think what a depressurization from 8,000' to 30,000', and then back down to 10,000 or so would look like on the charts for a person still offgassing from a dive. If any of you have information on this extremely unlikely situation, I would be genuinely interested to read it.
Feel free to take this information at the value of what you paid for it, but at least consider it before you hop on an airplane prior to waiting the interval recommended by your certifying agency...