How long should a person wait after scuba diving without a controlled ascent before flying to cabin pressure altitudes of 8,000 feet or less?

After scuba diving without a controlled ascent, a person should ideally wait at least 12 hours before flying to cabin pressure altitudes of 8,000 feet or less. This guideline is based on the principle of allowing sufficient time for the body to eliminate nitrogen that may have been absorbed during the dive.

When a diver ascends rapidly, nitrogen can form bubbles within the body, which, if not allowed enough time to dissipate, can lead to decompression sickness ('the bends'). Although the specific time required can vary based on multiple factors such as the depth and duration of the dive, it is generally recommended that a minimum of 12 hours be observed to minimize the risk of decompression illness. This precaution is critical, especially since flying exposes the body to lower atmospheric pressure, which could exacerbate any potential issues related to nitrogen bubbles.

A longer wait time, such as 24 hours, might be recommended particularly after deeper or more prolonged dives, but in the context of flying to altitudes of 8,000 feet or less, 12 hours is recognized as a safe minimum.