Boats are the means of transport most likely to cause motion sickness. Able to affect an occasional passenger as well as a seasoned sailor, seasickness, called naupathia, can cause symptoms much more serious than simple nausea.

WHAT CAUSES SEASICKNESS?

Seasickness appears when your brain receives contradictory information about the position of your body. Indeed, to maintain balance, your body has three types of information:

Visual information.
Vestibular information: collected in the inner ear, it informs us about the position of the head in space and the accelerations to which we are subjected. Disturbed, the vestibular system can cause dizziness.
Proprioceptive information, which comes from the muscles, tendons and sensory nerves, telling you for example the slope of the ground.

AM I NECESSARILY GOING TO GET SEASICKNESS?

The onset of seasickness depends on many factors, including the person concerned. We are not all equal when it comes to seasickness, and we don't really know why. Some people will never get seasick, while others will inevitably get it. You may also never have experienced seasickness and be very sick on your next outing. These variations depend on the state of the sea, calm or rough, the type of boat (zodiacs or, on the contrary, very large ships trigger seasickness less than a small sailboat), as well as your physical and psychological state.

WHAT ARE THE SYMPTOMS OF SEASICKNESS?

The symptoms are also very variable. They generally manifest themselves initially by a feeling of malaise, followed by nausea. Your face becomes pale, you salivate a lot and sweat. Seasickness can also cause severe drowsiness, or even confusion of the mind. Your discomfort can then obsess you, distracting you from any other thought, leading to panic attacks or severe depression. In general, the brain ends up adapting to this new situation and the signs of seasickness disappear after two to three days: this return to normal is called seasickness. In a few rare cases, seasickness takes much longer, or even never happens.

IS THERE A RISK TO MY HEALTH?

Seasickness, although often distressing, is generally not dangerous to your health. However, the drowsiness and confusion that can occur prevent you from doing certain activities (steering, working on the machines, etc.). In the case of severe seasickness that lasts for several days, force yourself to eat and hydrate properly, because repeated vomiting can lead to serious dehydration.

WHAT CAN I DO TO PREVENT THE EFFECTS OF SEASICKNESS?

The more fragile your body is, the more susceptible you will be to seasickness. Sailors often refer to the "4F rule", which groups together the main factors that promote seasickness:

• Cold. It is often colder at sea than on land: even in the middle of summer, wear warm, windproof clothing. The cold can make seasickness more likely to occur.
• Fatigue. Be well rested on the day of departure.
• Fright. The fear of getting seasick is often the trigger for the first symptoms. Take your mind off things, concentrate on a task to be done (taking the helm, going out on deck, etc.).
• Hunger. Eat small amounts of food regularly.

WHAT TREATMENTS ARE AVAILABLE TO ME?

There is no miracle treatment that would work for everyone, in all circumstances. There are various medications on the market to combat vomiting or the causes of seasickness. They must most often be taken before departure and can sometimes cause significant side effects, including severe drowsiness and concentration problems, which prevent certain activities from being carried out (diving, high-risk positions on the boat, etc.). Physiotherapy has recently begun to offer preventive techniques. Each session involves placing the patient in the conditions that cause seasickness, to gradually accustom the brain to this type of situation. This is called optokinetic or vestibular rehabilitation. Before you leave, ask your doctor for advice. He or she will be able to direct you to the most appropriate treatment. In addition, some medications are only available on prescription and have many contraindications.
When returning to land, some people suffer from "land sickness": dizziness, ground moving underfoot, and other symptoms similar to seasickness. However, the effects are less intense and often stop quickly.