How long should you wait before flying after scuba diving?

After a dive your body still holds extra nitrogen that it releases slowly at the surface. An airliner cabin is pressurised to a lower pressure than sea level, so flying too soon reduces the pressure around you while that nitrogen is still leaving your tissues — which can raise the risk of decompression sickness (DCS).

• One no-decompression dive: a minimum preflight surface interval of 12 hours.
• Multiple dives a day or several days of diving: a minimum of 18 hours.
• Dives with required decompression stops (or using heliox or trimix): substantially longer than 18 hours — DAN gives no single figure.

DAN notes that the research behind these numbers used dry, resting volunteers in a chamber, so longer intervals may be needed for divers who were in the water and working hard. Waiting longer than the minimum is the conservative choice.

Many dive computers show a no-fly countdown after a dive. Follow whichever is longer: the computer's figure or the DAN minimum for the diving you did.

DAN treats symptoms as the bigger problem: a diver with possible signs of decompression illness should get medical advice rather than board a plane. Joint pain, numbness, tingling, unusual fatigue or dizziness after diving are reasons to call a diving doctor or DAN before you travel.

On a Hurghada holiday the simplest rule is to keep your last day of diving at least a full day before your flight home — tell us your flight time when you book and we will plan your dive days around it.