For the avid diver, the question of when you can fly after a dive is a serious one. This is most likely because you are desperate to get the last dive in before having to get back on a plane and go home. However, flying too soon after diving can lead to very serious illnesses. Ascending to an altitude too quickly after diving can cause a significant risk of decompression sickness. Read on to find out more information on the dangers of flying after diving.
What is Decompression Sickness?
According to Henry’s Law of Scuba Gas Laws, a greater quantity of gas can be absorbed by a liquid if under pressure. So that means that your body, which is made up of over 60% of water, absorbs a greater amount of nitrogen gas from the scuba tank when you are diving. Usually, this is not an issue since the nitrogen gas leaves your body when you exhale. It also leaves through your skin. However, the water pressure causes the inhaled air to remain in your body rather than being dispelled. As you resurface, the pressure decreases and the nitrogen gas releases through your body’s tissues and into your bloodstream. This process is called off-gassing.
This is why divers take it slow when coming back up to the water’s surface. They may also stop part of the way up to allow any gas to diffuse. If you ascend too quickly, the nitrogen gas can form bubbles in both the bloodstream and body tissue which can cause major issues.
If these bubbles form in the bloodstream, it can restrict blood flow to your lungs, and send you into shock. If these bubbles form around the joints, it can be extremely painful. Worst case scenario, these bubbles form within the spinal cord or brain, and it can cause paralysis or even death.
DCS is further heightened when you fly. This is because there is a reduction in pressure with altitude. So the higher you guy, the lower the pressure. This reduced pressure can cause these nitrogen gas bubbles to expand, leading to a much higher risk of severe DCS.
How Long to Wait for Flying After Diving?
Unfortunately, there is no agreed-upon figure for how long you should wait to fly after diving. The US Navy suggests at least 12 hours, and the US Air Force suggests a full 24 hours.
The Divers Alert Network has the following guidelines for divers to follow.
- A diver should have a minimum preflight surface interval of 12 hours after a single no-decompression dive.
- A diver should have a minimum preflight surface interval of 18 hours if there have been several dives in one day or multiple days of diving.
- If the diving was decompression diving, an interval longer than 18 hours is suggested.
Please note that the above guidelines are for sports diving only. These guidelines do not apply to commercial diving or nitrox diving. Because DCS is complex and involves many other factors, there is no fixed flying after diving rule that can guarantee that you will not suffer from DCS.
Ready to Stay Safe After Your Dive?
Whether you wait 12 hours or 24 hours after diving, there are no absolute guarantees that you won’t get DCS when you fly. However, the longer your preflight surface interval time is, the more nitrogen you expel from your system which in turn minimizes the risk of the sickness. Although diving is exhilarating and fulfilling, making sure you stay safe and healthy afterward should always be a priority. Always check in with your body and make good decisions.