How long do I have to wait to fly after diving?
This is frequently asked question by divers who are wanting to fit just one more dive into the last day of their diving holiday. Despite the fact that you cover this topic in entry level dive courses for some reason many divers still do not understand the guidelines. This is probably because the recommendations change sometimes, and some divers are more conservative than others.
The current recommendation set out by PADI is: For single dives, a minimum pre-flight surface interval of at least 12 hours is recommended. For repetitive dives, or multiple days of diving a minimum pre-flight surface interval of at least 18 hours is recommended
This is just the PADI recommendation, DAN (Divers Alert Network) recommend 24 hours for repetitive dives, The US Air Force recommend 24 hours after any dive, while the US Navy tables recommend only 2 hours before flying to altitude. Maybe these massive differences are the reason why it is probably one of the most frequently asked scuba diving questions of time. The truth is that ascending to altitude immediately after diving puts you at risk of getting DCS (Decompression sickness). This is because after every dive our body is full of tiny bubbles, most of the time these bubbles are harmless and will work their way out of the body on their own in a few hours. However if you then ascend to altitude those tiny bubbles will expand (because air pressure is reduced at altitude) and if they expand too much they will cause the onset of DCS symptoms.
Another important truth is that these times set out by various agencies are not a hard rule. You could potentially get straight onto a plane after a dive and be fine, or you could wait 24 hours after a dive before flying and still develop symptoms of DCS. However the longer your pre-flight surface interval is, the more nitrogen has been expelled from your body, therefore the longer you wait before flying, the less likely you are to develop DCS.
We recommend that you use good judgement when deciding how long to wait before flying. For instance doing a Discover Scuba Dive is not going result in the same amount of dissolved gas as a dive to 40 metres. Using Enriched Air Nitrox will result in less gas being dissolved into your blood stream than diving with air would. Also you general health and age changes the way your body off gasses. The estimated probability for developing DCS for flying with a 12 hours surface interval is around 1 percent. Of the divers who fly home between 12 to 24 hours after their last dive, an estimated 0.004 percent of divers will develop symptoms of DCS, making this rule fairly safe.
However long you choose to wait before flying after diving, just remember to be safe and exercise caution whenever it comes to diving. Your health is more important than trying to squeeze that last dive into your holiday, use your last day exploring above the water, sightseeing or even snorkelling. That way you can be assured that you will be fit and healthy for your next diving holiday!
‘Flying after Diving’ was written by Mike