Unless you're super lucky (like we are), you have to travel by air to go scuba diving. An important thing to take into account when you're planning your dive holiday is your flight dates and times, which will determine your diving schedule. When you scuba dive, you get nitrogen build-up in your body, and you need to make sure you expel it to a healthy amount before going up to altitude. We get a lot of e-mails about this and there is often confusion about the rules, so we're going to break it down really simply to make your holiday scheduling even easier (hint on the guidelines: they're more relaxed than you think they are)!
Rule 1. You need 18 hours before you go to altitude
Different organizations will say different things when it comes to the hours required on land before going to altitude, but PADI currently states that you need 12 hours before you fly if you do one dive and 18 hours if you're doing multiple dives over multiple days. This means that if you've been diving for a week and you're flying out at 1PM, you can dive up to 7PM the day before safely.
A lot of people like giving themselves 24 hours to be on cautious side, and because they'd like to just spend some time relaxing on the beach on their last day of holiday, and you are of course welcome to give yourself as many hours as you want. But if you're a dive freak, 18 hours is what you need, even if you're diving a lot from a liveaboard. As always, though, make sure to practice conservative dive practices and avoid pushing your no-decompression limits when you dive.
Rule 2. Altitude doesn't just mean flying
If you dive, and then are planning on driving up the mountains to get to your next destination, this still counts as altitude. Anything above 300 meters/1000 feet counts as altitude because the atmospheric pressure drops, so keep this in mind when you're planning your post-diving travels. If you need to drive over the Colorado Rockies to get home, give yourself the appropriate time before making the trip to make sure you're safe.
Rule 3. You can dive right after flying
There is a common misconception that, similar to needing time before you fly, you also need to wait after flying as well. The reason you shouldn't fly right after diving is because of the nitrogen build-up in your body, but you won't have that if you just got off a plane. You can literally jump from the plane into the water directly if you want to, although we wouldn't recommend doing that unless you're a professional stunt person.
So that's it, the 3 super simple rules to follow when it comes to flying and diving. Easy, right? Have a great dive holiday, and we hope we can dive with you all some day.