Flying After Diving
Flying (or otherwise ascending) to a higher altitude after having dived can predispose a diver to decompression illness unless there has been sufficient surface interval to allow excess gas to diffuse from the body. If insufficient time has been allowed and the ambient pressure is reduced, gas bubbles may form, or existing asymptomatic bubbles may increase in size and cause symptoms of decompression illness.
We can never be sure exactly when it becomes "safe to fly" after a dive since it will depend on the degree of bubble formation and how long it persists.
Many authorities recommend that, as a general rule, a diver should wait at least 24 hours before flying after an air dive. Sometimes this may be overly conservative, while on other occasions, it may not prove to be conservative enough.
(Reprinted from The DAN Emergency Handbook.)
The following recommendations, which apply to recreational divers, represent the consensus reached by attendees at the 2002 Flying After Diving Workshop. The recommendations are based on earlier published work and recent experimental trials as described in the Workshop Proceedings.
They apply to air dives followed by flights at cabin altitudes of 2,000 to 8,000 feet (610 to 2,438 metres) for divers who do not have symptoms of decompression illness (DCI). The consensus recommendations should reduce DCI risk during flying after diving but do not guarantee avoidance of DCI. Preflight surface intervals longer than the recommendations will reduce DCS risk further.
Dives within the No-Decompression Limits
A Single No-Decompression Dive:
A minimum pre-flight surface interval of 12 hours is suggested
Multiple Dives per Day or Multiple Days of Diving: A minimum pre-flight surface interval of 18 hours is suggested.
Dives Requiring Decompression Stops
There is little experimental or published evidence on which to base a recommendation for decompression dives. A pre-flight surface interval substantially longer than 18 hours appears prudent.
If a diver has had decompression illness and has not received appropriate recompression treatment, flying can be risky even more than a week after the dive.