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Flying After Scuba Diving: How Long Should You Wait?

Flying After Scuba Diving: How Long Should You Wait?

Written by Scuba.com
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Updated on August 2, 2023
Airplane flying over the ocean

Divers are always keen to squeeze in a few extra dives before leaving a particular destination. After all, we want to make the most of our diving trips, don’t we? Perhaps you heard of a new shipwreck to explore that you didn’t know about earlier, or maybe a fellow diver tipped you off about the presence of some interesting marine creatures at a nearby dive site. And being a curious and intrepid ocean lover, you simply couldn’t pass up the chance to see these wonders since it may be a long time before you can come back to whichever country or island you’re currently visiting.

Whatever your reasons are, you’re probably wondering whether it’s safe to dive on the day of your departure or the evening before your early flight. This dilemma often crops up for scuba divers, as diving and flying are two activities that often overlap, and if you don’t plan properly, it could lead to severe—and potentially fatal—health complications.

You’re probably already aware that it isn’t advisable to fly so quickly after diving, but the question remains: How long do you really have to wait?

Concerns About Flying & Scuba Diving

Scuba diving and flying don’t mix due to their inherent physiological differences and the risks they pose. Scuba diving exposes individuals to increased atmospheric pressure, causing the body to absorb more nitrogen. Ascending too quickly can lead to decompression sickness. On the other hand, flying involves rapid altitude changes and decreased pressure, potentially causing nitrogen bubbles to expand dangerously. Additionally, flying immediately after diving can impair judgment and increase the likelihood of hypoxia due to residual nitrogen in the body.

Combining these activities increases the chances of serious health complications, making it essential to observe safe intervals between diving and flying to ensure the well-being of divers and passengers alike.

How Much Time Should You Wait Before Flying?

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Unfortunately, there’s no straightforward answer to this question. It all boils down to the risk you are willing to take, as well as the maximum altitude you will be flying at and whether your dives involved decompression stops.

Nonetheless, to give you a rough idea of how long you should wait, several organizations have provided their take on the matter.

The U.S. Navy recommends that you wait at least two hours before you board a plane after scuba diving, while the U.S. Air Force says you should wait 24 hours. The Divers Alert Network (DAN) recommends a 12-hour minimum surface interval before flying, and the Professional Association of Diving Instructors’ (PADI) Flying After Diving guidelines say divers should not ascend to a high altitude within 12 hours of completing a single dive or 18 hours after doing multiple dives (whenever possible, wait 24 hours).

Recommended Time to Wait After Diving

OrganizationRecommended Surface Interval Before Flying
Divers Alert Network (DAN)12 hours (minimum)
U.S. Air Force24 hours
U.S. Navy2 hours
Professional Association Of Diving Instructors (PADI)12 hours (for single dives)
18 hours (for multiple dives)
24 hours (ideal recommended interval)

These recommendations are conflicting, to say the least. So which guideline should you follow? The current winner of the debate is the DAN guideline, which states:

  • After single no-decompression dives, a minimum pre-flight surface interval of 12 hours is suggested.
  • After multiple no-decompression dives per day or multiple days of diving, a minimum pre-flight surface interval of 18 hours is suggested.
  • For dives requiring decompression stops, there is little experimental or published evidence on which to base a recommendation; for decompression diving, a pre-flight surface interval substantially longer than 18 hours appears prudent.

Note: The above info is for sports diving and should not apply to commercial diving or nitrox diving. Because of the complex nature of decompression sickness (DCS), and because decompression schedules are based on unverifiable assumptions, there can never be fixed flying after diving rules that can guarantee prevention of bends completely.

Whether you wait 12 hours or 18 hours (or more), there are no guarantees that you won’t get decompression sickness (DCS) when you fly. Of course, the longer your pre-flight surface interval time, the more nitrogen you expel from your system—which minimizes the risk of decompression sickness.

Using Scuba Dive Computers to Calculate Wait Times

scuba dive computer on top of fins, mask, and snorkel
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As a diver, you most likely already own a dive computer. But if you don’t, it would probably be a good idea to purchase one. It would help take most of the guesswork out of the whole flying after diving dilemma, as some of the best dive computers available today should have the capability to make the necessary calculations and provide you with the most optimum “time to fly” based on your dive parameters.

Renting a scuba dive computer isn’t advisable if you plan to do multiple dives on different days. You’ll need to use the same computer during each dive for maximum accuracy—the computer will be using the information from all of your dives to be able to give you the right “time to fly” calculation.

If you must rent, make sure to rent it for the entirety of your trip (if possible) to ensure that no one else uses it, as this will obviously skew the calculations.

The Risk of Flying After Scuba Diving

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Truthfully speaking, ascending to a high altitude immediately after diving increases a person’s risk of suffering from decompression sickness. Flying after diving increases this risk because of the decreasing atmospheric pressure as you ascend. Airplane cabins may be pressurized, but they only go up to around 11 or 12 pounds per square inch (psi) at cruise altitude. This is still a significant decrease from sea-level pressure, which is approximately 14.5 psi.

You might only have a few tiny bubbles in your body when you reach the surface after a dive, which should cause no problems at all. However, if you go flying immediately without waiting a sufficient amount of time, these small bubbles could expand (due to the reduction in pressure with altitude) and could cause the onset of DCS symptoms.

Recommended Pre-Flight Interval After Scuba Diving

There are many ways to avoid getting decompression sickness altogether, but we recommend you use your judgment and consider some factors before deciding how long to wait before flying after a dive. As previously mentioned, these include the number of dives undertaken during the trip, the type or types of dives (decompression, non-decompression, altitude dives, nitrox, etc.) you engaged in, your general health, body type, and your age.

The estimated DCS probability for the 12-hour flying-after-diving surface interval is about one percent. Of the 300,000 to 400,000 people who fly home 12 to 24 hours after their last dive, the estimated incidence of decompression sickness among these divers is about 0.004 percent, making the 12- to 24-hour rule the most followed among divers around the world.

If you’re still unsure and you just want to play it safe, the best thing to do is to plan ahead and allow one day (precisely 24 hours) between your last dive and your flight. An even better (and safer) option is to wait two whole days, particularly if you engaged in deep or multiple dives.

What You Need to Remember When Flying After Scuba Diving

passengers flying on a commercial airplane
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Now that you have a general idea of how long you need to wait before flying, it’s important to educate yourself on some of the things you need to be aware of before you board that plane.

Here are a few key things divers need to remember, according to the Federal Aviation Administration (FAA):

  1. Wait at least 24 hours between diving and flying.
  2. Familiarize yourself with the symptoms of DCS so you can monitor yourself and your companions.
  3. You’re at risk of suffering altitude DCS whenever you fly in an unpressurized aircraft above 18,000 feet. If you went diving before the flight, you’d still be at risk even at much lower altitudes.
  4. Breathing 100% oxygen at any time during the flight does not prevent altitude DCS. However, if you were able to perform oxygen pre-breathing before take-off, this should greatly help reduce the likelihood of suffering from DCS.
  5. Even in a pressurized aircraft, you may still experience altitude DCS as a result of sudden cabin pressure loss during in-flight rapid decompression. If this happens, refrain from flying again for at least 24 hours. Also, make sure to watch for delayed DCS symptoms and seek medical attention at once.
  6. If you experience symptoms in-flight and they go away during the descent of the plane, this does not mean that you are fine. It may actually be confirmation that you are experiencing altitude DCS, in which case you should get yourself evaluated by a medical professional immediately.
  7. Refrain from flying again if there has been any indication that you experienced DCS. Get yourself cleared by an FAA medical officer, aviation medical examiner, military flight surgeon, or hyperbaric medicine specialist before attempting to board another flight.
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