Flying After Diving

Question:

I've seen some irresponsible divers who fly less than 12-hours after diving not get bent, while others that wait more than the prescribed 24-hours do. Why does this happen?

Answer:

I can understand your irritation that divers who ignore the guidelines for flying after diving can get away with it while others who are cautious and careful may get decompression sickness (DCS). Alas, that is life! I see heavy smokers puff away all their lives and never get a chest infection or lung cancer, while a non-smoker may suffer chronic bronchitis or get a cancer. We know there are risk factors for these illnesses but there is also a huge personal susceptibility.

Why some individuals are more susceptible to DCS we do not know. There may be some genetic factors affecting susceptibility. However, individual susceptibility can also vary from day to day depending on factors such as exercise, hydration, alcohol, smoking and anxiety. The current state of health may also be a factor as a heightened immune response may react more readily to decompression bubbles and cause symptoms. This is one reason we encourage people not to dive unless they are well. A diving profile tolerated one day may result in DCS the following week. I cannot explain it all; all I can do is advise you to follow the guidelines and leave others to take their risks.

The DAN guidelines for flying after diving are:

For a single no-decompression dive, a minimum pre-flight surface interval of 12-hours is suggested.

For multiple dives per day or multiple days of diving, a minimum pre-flight surface interval of 18-hours is suggested.

For dives requiring decompression stops, there is little evidence on which to base a recommendation. A pre-flight surface interval substantially longer than 18 hours appears prudent.

Answer provided by Dr John Parker, who is a Diving physician and Senior Dive Medical Consultant for DAN Asia-Pacific.

DAN Asia-Pacific Executive Director, John Lippmann, comments further:

There is no magic and safe interval for flying after diving. The risk of DCS precipitated by flying reduces with time, and the longer the surface interval, the lower the risk. We generally encourage divers to wait 24 hours before flying after a dive.

If you have symptoms after diving and you are planning to fly (or drive to altitude), we suggest that you call a DAN-supported diving hotline and seek advice prior to doing so. Sometimes symptoms can worsen significantly during or after being at altitude.

See Flying After Diving