The recommended minimum surface interval between flying and diving is related to the risk of decompression sickness (DCS). Flying after diving exposes the body to a lower atmospheric pressure, similar to ascending during a dive. If residual nitrogen remains in the body from a recent dive, this pressure reduction can cause nitrogen to form bubbles, leading to DCS. A longer surface interval allows more nitrogen to be eliminated, reducing this risk. For example, a single no-decompression dive typically requires a minimum surface interval of 12 hours before flying, while repetitive dives or dives requiring decompression stops necessitate a longer interval, often 18 hours or more.
Adhering to safe surface intervals is crucial for diver safety. DCS can manifest in a range of symptoms, from mild joint pain to serious neurological issues or even death. By allowing sufficient time for nitrogen to off-gas before flying, divers significantly reduce their susceptibility to this potentially life-threatening condition. The guidelines developed by diving organizations are based on extensive research and aim to minimize the incidence of DCS. Historically, the understanding of DCS and its relationship to flying has evolved, leading to more conservative recommendations to enhance diver safety.
