Flying After Diving
Divers Alert Network (DAN)
Courtesy of DAN
In the past, guidelines for flying after diving were quite varied. For example, after a single no-stop dive, the U.S. Navy recommended a two-hour surface interval time (SIT), DAN recommended 12 hours SIT and the U.S. Air Force recommended 24 hours SIT. And in 1989, the Undersea and Hyperbaric Medical Society (UHMS) recommended curtailing all diving within 24 hours of a flight and up to 48 hours following a decompression dive.
These guidelines proved to be a serious restriction for divers and dive operators, so in 1991, DAN Researchers developed a series of experiments designed to produce the data that was desperately needed to refine these guidelines.
The objective of these studies was to estimate the relationship between the preflight surface interval and decompression illness (DCI) incidence for a few dive series representative of recreational diving. A preflight surface interval was accepted or rejected within the study based upon the number of DCI incidents and total exposures. Acceptance and rejection rules were chosen to allow mild DCI but limit more serious DCI. The Duke Institutional Review Board of Duke Medical Center approved these rules.
With the data collected from these studies, DAN was able to develop more specific guidelines that still reduce the risk of decompression sickness as a result of flying after diving. DAN’s initial “Flying After Diving Trials” laid the foundation for the current flying-after-diving guidelines for recreational divers and then prompted the U.S. Navy to update their residual nitrogen-based flying-after-diving rules.