Current Research

Realizing that just about all current recommendations for flying after diving are based mostly on "best guess" and not hard data, Dr. Richard Vann and Dr. Wayne Gerth launched DAN’s Flying After Diving study in 1993 at F.G. Hall Hypo/Hyperbaric Laboratory at Duke University Medical Center. So far they have completed 700 exposures, with 38 cases of decompression sickness (DCS) recorded.

All cases of DCS after a single no-decompression dive have occurred when the pre-flight surface interval was 12 hours or less.

After a repetitive dive, DCS occurred even at pre-flight surface intervals as long as 17 hours. The data so far suggested that the original recommendations of waiting 12 hours or more after making a single no-decompression dives is reasonable. In addition, current research suggests that it may be wise to wait 17 hours or more after making repetitive dives. However, the research is as yet incomplete and further work is continuing. More specific data on DAN’s FAD recommendations are scheduled for a future issue of Alert Diver.

The one unshakable truth is that longer the surface interval after diving, the less the risk of DCS when flying afterward.

Remember chamber trials are conducted within a relaxed, dry environment unlike the open water, where the multiple stresses of diving conditions may adversely affect the rate of inert gas uptake and elimination.

Extended surface intervals allow for additional denitrogenation and may reduce the likelihood of developing symptoms. For those diving heavily during an extended vacation, it may not be a bad idea to take a day off at midweek, or save the last day to buy those last-minute souvenirs.

Have A Dive Medical Question?

Call DAN’s Dive Safety and Medical Information Line at:

(800) 446-2671 or (919) 684-2948 ext. 222

Visit DAN on the World Wide Web at:

COZUMEL October 7, 1998