Why should divers avoid flying shortly after diving?

Divers should avoid flying shortly after diving primarily to reduce the risk of decompression sickness (DCI). When a diver ascends to the surface, nitrogen that was absorbed into the body while under pressure can form bubbles if ascent is too rapid or if ambient pressure changes too quickly, such as during a flight.

The body needs time to safely off-gas nitrogen after diving, which is why specific surface intervals are recommended before ascending to high altitudes. Once at altitude, the reduced pressure can exacerbate the situation, preventing the nitrogen from leaving the body efficiently and increasing the likelihood of bubbles forming, which can lead to DCI.

In contrast, hypothermia related to altitude is less of a concern because temperature does not directly correlate with the risk of decompression; while it's essential for divers to maintain body temperature during and after diving, this is not the primary reason for waiting before flying. Ensuring tanks are fully pressurized or air supply stabilization also does not directly relate to the risks associated with flying post-dive. Therefore, focusing on the risk of DCI is critical for divers planning to fly after a dive.