Are you Flying after Diving?
It is recommended that you do not fly immediately after diving.
When a diver breathes compressed air from a scuba tank, the surrounding pressure causes the nitrogen to enter the body which is then stored in the tissues. The longer and deeper the dive, the more nitrogen is absorbed.
Using a safe ascent rate (the speed at which you go up towards the surface) allows the nitrogen to leave the tissues safely after a dive.
When you leave the water, you will begin to off-gas (get rid of excess nitrogen by exhalation). The longer you stay on the surface (ie. not under water but at sea level / one atmosphere of pressure) the more you continue to off-gas until you are rid of any nitrogen.
Going to altitude or flying very soon after diving is the same as ascending too quickly from a dive because the pressure surrounding you decreases. Which means any residual nitrogen still dissolved in your bloodstream may come out of solution as bubbles if the pressure reduction is not slow enough for your body to off-gas safely. These bubbles are what causes Decompression Sickness.
Staying at ground level before flying is akin to doing an in-water decompression stop (waiting at a prescribed depth for a length of time to allow off-gassing). Deeper and longer dives mean there will be more residual nitrogen in your body, thus requiring a longer surface interval before flying.
How long should I wait before flying?
The time you should wait depends on the diving you have done.
The Divers Alert Network (a non-profit medical and research organisation dedicated to the safety and health of recreational scuba divers) recommends a surface interval of 24 hours or more before flying after diving.
This allows for any unexpected problems such as loss of cabin pressure during a flight.
Alternatively, you can follow the minimum guidelines established by DAN and the Undersea and Hyperbaric Medical Society for flying in commercial pressurised aircraft (Sheffield and Vann 2004):
• A single dive within the no-decompression limits: 12 hours
• Repetitive dives of multiple days of diving: 18 hours
• Decompression dives (planned or unplanned): substantially greater than 18 hours
It is important to remember:
- Planning conservatively is a good way to stay out of trouble.
- Recommended pre-flight surface intervals do not guarantee avoidance of DCS. Longer surface intervals will reduce DCS risk further.
- These guidelines apply to divers who have not experienced any DCS symptoms. If you have experienced DCS symptoms, you should be medically evaluated, if possible, before flying.
- If you are diving on holiday your insurance policy may include a restriction and your holiday dive centre or liveaboard may enforce it but ultimately it is your responsibility.
If you are diving with Red Duck Diving, you must inform us if you are flying in the 48 hours following your dive.