Divers Alert Network (DAN) and the Professional Association of Diving Instructors (PADI) clarify the current safety recommendations of how soon divers can fly to altitude after using scuba underwater.
The information in this guide explains the recommended flying after diving guidelines and why you have to wait to fly after scuba diving.
Air travel (or otherwise ascending to a higher altitude) having already dived, can predispose a diver to decompression sickness.
Hence, there needs to be sufficient surface interval time to allow any excess gas to diffuse from the body.
So why does it matter?
Gas bubbles may form if you go to altitude (e.g. fly in a plane) because the ambient pressure will reduce. Furthermore, existing asymptomatic bubbles can increase in size - causing DCS symptoms.
Divers can never be exactly sure when it becomes 'safe to fly' after a dive, since it will depend on the amount of 'bubble formation' and how long the malady persists.
As a general rule of thumb, many of the leading scuba authorities recommend waiting at least twenty four hours before flying after making an air dive.
Sometimes this may seem overly conservative. But, on other occasions it may not be conservative enough, since there are no hard and fast flying after diving rules.
This part is important:
If you have had symptoms of decompression illness, and have not received appropriate recompression treatment, flying can still be risky even a few weeks later.
After a long flight, we often feel jet-lagged and dehydrated. Since we may have an increased susceptibility to DCI in this condition, it is not advised to use scuba again until you have made a complete recovery from the flight.
Note: Divers should never underestimate the importance of having adequate scuba diving insurance and what the different packages cover.
You should avoid going to the top of a mountain after breathing from a scuba cylinder underwater. This is because being at the summit of a 3,048 metre mountain (10,000 feet high) may also put you at risk for Decompression Sickness.
Altitude is also a major concern when ziplining as an activity because it usually takes place in the mountains. Thus, try to confirm the altitude of the venue and always zip with extra caution.
Note: The cabin pressure inside most commercial jets has the same effect as being at 1800 to 2400 metres above sea level (6000 to 8000 feet). Another section explains how dive tables and computers work.
The Divers Alert Network says "gentle relaxation massages have not been 'confidently' associated with DCS cases". Nevertheless, some experts express caution about getting a deep tissue massage immediately after diving.
There are two main concerns with deep tissue massages:
Relaxing in a hot tub sounds like the ideal post-dive treat. But, circulation usually improves as the body warms up which may, in turn, increase the likelihood of bubble formation.
Consuming copious amounts of alcohol causes dehydration and may delay the diagnosis of DCS. Always drink lots of water before and after diving, and especially before unwinding with an alcoholic beverage.
There is little experimental or published evidence on which to base a recommendation for decompression dives.
Diving at 300 metres (1000 feet) or greater requires the use of special training and procedures. Another section explains more about Altitude Diving.
Many scuba divers are freedivers as well. Generally, members in the freediving community recommend applying the same flying after scuba diving guidelines, that being:
Note: The manufacturers of many modern dive computers instruct divers to wait for longer periods of time.
According to the (US) National Institute of Health (NIH), there have been at least ninety recorded cases of DCS following a repetitive breath-hold dive.
In fact, Herbert Nitsch (the freediving world record holder) also suffered from DCS. As a result, he came close to being paralyzed for life.
DAN (and the NIH) both recommend freedivers to consider the uncertain risks of DCS after making multiple deep dives. The precautions they recommend include:
There is very little data about flying after deep freediving. Hence, the recommendations are to wait 18 to 24 hours after making deep freedives before getting on a plane.
Many in the freediving community use a four to six-hour pre-fly interval because freedivers remain at depth only briefly and the 18-24 hour recommendation is based on research with scuba divers.
Casual snorkeling activities to shallow depths do not have any major issues with dissolved nitrogen. But, it may be a concern for constant weight freedivers who also scuba dive. Hence, you should avoid participating in recreational open water or constant weight freediving after scuba diving on the same day.
Note: The PADI Emergency Action Plan for scuba accidents is an important tool to follow when carrying out any in-water rescues.