Tips for preventing seasickness when diving

What causes seasickness? 

Seasickness is a type of motion sickness that's completely harmless but fairly common. Generally speaking, nearly 25% of the population are affected, though a true estimation is hard to come by as seasickness can be momentary: just because you're seasick once doesn't mean it will happen again, and vice versa. The phenomenon is primarily a balance problem - an inner ear dysfunction, to be more precise. Seasickness comes from a confusion between what you're seeing and what you're feeling (sensory mismatch): your eyes see a fixed point while your ears are detecting movement. This is how seasickness hits, as your brain is receiving totally contradictory information. These contradictions bring about several symptoms which can be more or less intense depending on the person, such as nausea, vomiting, headache, fatigue, and so on.

Plan ahead to prevent seasickness 

To prevent seasickness, there's a simple rule that's easy to remember: ACHE (Anxiety, Cold, Hunger, Exhaustion). These 4 factors contribute the most to seasickness. Which is why it's important to anticipate them to keep from getting sick once on board... This is also true before diving, as the golden rule before jumping in is to be in good health! You get it: it's best to plan ahead before setting out. To do so, remember to cover up while travelling to your diving spot, stay hydrated, don't set out on an empty stomach, be in good health, and finally, remember to stay calm even if weather conditions aren't ideal. Also avoid staying next to the engine as odours coming off it can make you nauseous. Here's another little tip: keep your eye on the horizon. This can help get over seasickness if needed.

What do you do if you're seasick at the surface or underwater?

While seasickness most often comes while you're on a boat, it can also hit you once you're in the water at the surface. All it takes is a bit of sea surge and nausea take over. When this happens, the best thing to do is submerge yourself and wait for it to pass. The nausea will usually go away and you can enjoy your dive, even if that seemed impossible a few minutes earlier. That said, it's very possible to be seasick once you're under water... Especially during stops when there's heavy swell. If you start feeling seasick underwater, it's important to find a fixed point to focus on until the nausea passes. If the nausea won't go away, there's only one solution left: vomit into your regulator. Even if it's not the greatest of solutions, it's what you have to do! Don't worry, doing so will not alter your regulator's operation.

Tips for preventing seasickness at the surface

What seasickness treatments exist?

Be careful when taking medications for seasickness. Traditional seasickness treatments are medicines (such as Mercalm, Nausicalm, etc. in France) which are often dimenhydrinate-based, and can cause dangerous side effects for divers...  Among these side effects is dry mouth, and, more seriously, reduced alertness. These types of medications are not recommended for divers as the side effects can even cause nitrogen narcosis in some cases. If you dive, try homoeopathic remedies such as Cocculine (in France), which does not have side effects. The best thing to do is talk with your doctor to find the best solution for you.



Baptiste, Subea digital manager


Digital manager - padi rescue and level 1 ffessm

I'm Subea's Digital Manager. I'm passionate about spear fishing and free diving, and have been scuba diving for over fifteen years. I dive alone down to 60 meters.