Many recreational divers enjoy both freediving and SCUBA diving. A question that has been asked time and time again is this: Is it safe to freedive after SCUBA? If so, how long should one wait? If not, why not? Here, we’ll take a few moments to address some common concerns in order to help you make an educated decision about whether or not you ought to take the plunge.
Physical Risks Associated with Freediving after SCUBA Diving
Depending on the depth and duration of your dives, you might want to enjoy a long surface interval before freediving or even snorkeling after SCUBA diving, particularly if you’ve been breathing air instead of Nitrox. Your risk of DCS may increase if you freedive after SCUBA diving. This is due to the fact that repeatedly descending and ascending can change the destination of VGE (venous gas emboli) – commonly known as bubbles – present in your bloodstream after diving. In addition, when you hold your breath while diving, dissolved inert gases build up quickly; so, if you have any gases remaining in your blood after SCUBA diving, then you will be at an increased risk for developing decompression sickness.
Additional risks include brain bleeding caused by extreme blood pressure variation, arterial gas embolisms caused by lung damage, and oxygen depletion, which can cause hallucinations, nausea, and other dangerous side effects. While these risks are small, particularly if you’re not diving deep, they do exist.
How to Cut Your DCS Risk
In order to reduce the risk you’ll suffer from decompression sickness by freediving after SCUBA diving, it is vital that you pay very close attention to dive profiles, and if you’re at all in doubt about whether your plans are safe, give your body more time to adjust between dives. You will be at a higher risk for developing DCS if you have been making several dives each day, particularly if you have been taking only short surface intervals. In addition, your risk will increase if you have been flying, or if you have made major altitude changes during the course of your travels.
If you want to continue to enjoy the water after diving, but you know it’s not safe to freedive, then snorkel at the surface, breathing continuously, so long as conditions allow for it. You’ll be expending very little energy, and you will not be putting yourself at increased risk of developing decompression sickness.
It is very important to remember that DCS can take time to manifest. In some cases, it can take longer than 12 hours for symptoms to show, and by then, it might be too late to reverse all the damage decompression sickness can cause. Barotrauma is painful and can be life-threatening. If you have to make a choice between your own health and safety or another trip to the bottom, remind yourself that it is always best to err on the side of caution, no matter what. After all, spending your surface interval reading a book, lounging by the pool, or napping isn’t such a terrible thing.