Scuba diving before flight
Diving supersaturates tissues with nitrogen (TC AIM AIR 3.4).
- Pressure rises 1 atmosphere per 33 ft (10 m) of descent.
- Breathing pressurized air at depth for more than a few minutes causes it.
- Nitrogen must leave the body before cabin pressure falls.
Wait before flight (TC AIM AIR 3.4):
| Dive | Flight altitude | Wait |
|---|---|---|
| Under 33 ft, no decompression stops | Up to 8,000 ft ASL | 12 hours |
| Needed decompression stops | - | 24 hours |
| Any | Above 8,000 ft ASL | 24 hours |
- Above 8,000 ft ASL: even a pressurized cabin can lose pressure.
- Decompression sickness normally doesn't occur below 20,000 ft ASL.
- Diving before flight can trigger it at much lower altitudes: reason for the wait (TC AIM AIR 3.4).
Trap: assuming 12 hours always applies. Only a no-stop dive with flight below 8,000 ft; decompression stops or flight above 8,000 ft mean 24 hours.
References
- TC AIM AIR 3.4