I recently received my advanced open-water certification and am planning my first international dive trip. Of course I’ll want to dive as much as possible, but I know I have to consider my return flight. What are your recommendations for flying after scuba diving?

Whether they’re heading to the Great Lakes or the South Pacific, divers need to be cognizant of the effects of air travel on their bodies, which include an increased risk for decompression sickness (DCS).

Decompression Stress
The key reason post-dive air travel increases decompression stress is that the pressure in an aircraft cabin is lower than ground-level atmospheric pressure. To put this in perspective: Imagine you have just completed a dive to 66 feet, where you experienced an underwater pressure of 3.0 atmospheres absolute (ATA). The 1.0 ATA pressure at sea level has already subjected your body to a threefold reduction in pressure. If you then get on a plane that has a cabin altitude of 8,000 feet, with an associated pressure of about 0.76 ATA, you are now experiencing a fourfold reduction in pressure. Furthermore, should your plane suffer an unlikely cabin depressurization, you would be subjected to much greater decompression stress. For this reason, you will want to make sure you have sufficiently off-gassed before you board your flight.

Guidelines for Post-Dive Air Travel
DAN and the Undersea Hyperbaric Medical Society (UHMS) held a workshop in 2002 to review the available data regarding post-dive air travel. The following table outlines their recommendations for the absolute minimum time interval you should wait to fly after diving:

Important Qualifications
As a general rule, it’s a good idea to wait longer than the suggested minimum interval. Recent research shows that flying in a commercial aircraft even after a 24-hour surface interval can produce bubbles in a diver’s blood; therefore, DAN advises you to exercise caution by maintaining more conservative dive profiles during your final day of diving and planning for a 24 hour surface interval before flight. You can make the most of it by planning a topside excursion for the final day.

It is also important to remember that any post-dive ascent to a higher altitude — even using ground transportation — increases decompression stress, so follow the same guidelines if you’re heading by car, bus or foot from your dive site to the mountains.

For more information, visit DAN.org/Health.

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