Flying after Diving Guidelines

Safety is a huge part of scuba diving; Following No Decompression Limits, ascending slowly, staying close to your buddy, and checking air consumption regularly. But the safety does not end when you are back on the boat. There are a few things to keep in mind in the hours after a scuba dive, in order to stay safe and healthy.

As scuba divers learn in their courses, we accumulate nitrogen when we dive. The deeper you dive, the more nitrogen our bodies take on. We ascend slowly and do our safety stops to give that nitrogen time to "off-gas" while we are still under the water. Ascending too quickly, or skipping safety stops may result in the nitrogen forming little bubbles in the blood, and this is what causes decompression sickness.

If you have taken a scuba diving course, you will no doubt have been told about this important rule: Do not fly after diving!

The general rule for flying after diving is to wait 12 hours after one dive, and 18 hours after two or more dives. If you went over your no decompression limits, or missed a safety stop on the dive, it is advised to wait 24 hours.

This is because when we go up in an airplane, the altitude increases, so the air pressure is lower than it is at sea level. This can encourage the nitrogen you have accumulated on the dive to expand too quickly (a similar effect to ascending too fast) and this is what causes decompression sickness.

It is also advised to avoid going up mountains that are higher than 1,000ft (300m) for 24 hours after diving. For the same reasons as flying; The altitude is higher than at sea level, which creates an increased difference in pressure between your surroundings and the nitrogen in your body from the dive. The nitrogen expands too quickly and decompression sickness becomes a risk.

It is important to consider these risks when planning your vacation itinerary: Do not dive on your last day, and do not climb any mountains after a dive.