Long-distance air travel crossing several time zones in a short time causes jet lag syndrome (also called Rapid Time Zone Change Syndrome) upon arrival, because our circadian rhythm established at our origin is out of sync with the day-night cycle at our destination. Symptoms include feeling sleepy, hungry and alert at the wrong times. This affects our social life and ability to work or exercise. Fortunately within days our internal clock synchronizes with the environment. The more time zones we cross, the greater the expression of the syndrome and the longer it takes to overcome.
Divers often travel to faraway dive locations and may be affected by jet lag for the better part of their trip. The jet lag may affect one’s ability to dive safely; therefore, divers need to know how to minimize its effects.