Seasickness can turn a perfect day on the water into hours of misery, and it affects beginners and ocean veterans alike. The good news is that most sailors can prevent it, or at least keep it manageable, with a few habits before departure, smart choices on board and, where appropriate, medication taken early.

Quick answer: to prevent seasickness on a sailboat, get a good night’s sleep, skip alcohol the night before, eat a light meal, and if you are prone to it, take a motion sickness medicine before you leave the dock (ask a doctor or pharmacist which one suits you). On board, stay in the cockpit near the middle of the boat, watch the horizon, take the helm if you can, avoid reading or working below, and keep sipping water.

What Causes Seasickness?

Seasickness is a form of motion sickness. The most widely accepted explanation is sensory conflict: your inner ear feels the boat rolling, pitching and heaving, while your eyes, especially below deck, report that the cabin around you is standing still. When the signals from your balance system, eyes and body don’t agree, the brain responds with nausea, yawning, cold sweats, headache, drowsiness and eventually vomiting.

A few points worth knowing:

• Almost anyone can get seasick in the right conditions. Some people are simply far more susceptible than others.
• Children roughly between 7 and 12 tend to be very susceptible, while toddlers under two rarely suffer.
• Most people adapt after two or three days at sea as the brain gets used to the motion. Sailors call this “getting your sea legs,” and it can fade again after time ashore.
• Fear, anxiety, fatigue, heat, fumes and strong smells all make it worse.

Before You Sail: Sleep, Food and Alcohol

Prevention starts the day before. Many seasick episodes have less to do with the waves than with a late night, a heavy breakfast and a long drive to the marina.

• Sleep well. Fatigue lowers your tolerance. On longer passages, a sensible watch system matters for the same reason; see our tips to sleep comfortably while sailing.
• Go easy on alcohol the night before and while under way. A hangover and seasickness feed each other.
• Eat light and plain. An empty stomach is not the answer, but a big, greasy or spicy meal is worse. Crackers, bread, plain pasta, bananas and similar simple foods are easy on the stomach. Our guide to the best food to bring on a sailing trip has more ideas.
• Hydrate. Start the day well hydrated and keep water handy in the cockpit.
• Check the forecast. Short, steep seas against the tide or a leftover swell are the classic triggers. If you are introducing new crew to sailing, pick a calm day.
• Prepare the boat in harbor. Plan the route, stow gear, make sandwiches and fill thermoses before leaving, so nobody has to spend time head-down in the galley or at the chart table once the boat is moving.

Medications and Patches

For people who know they are prone to seasickness, medication is often the most reliable tool. The single most important rule: take it before you go, not after symptoms start. Once you feel sick, the stomach slows down and tablets are absorbed poorly, if you can keep them down at all.

The options commonly used for motion sickness include:

Type	Examples	Things to know
Sedating antihistamines	Meclizine, dimenhydrinate, cinnarizine (outside the US), promethazine	Widely used; several are sold over the counter in many countries. Drowsiness is the main side effect, and some are more sedating than others.
Scopolamine (hyoscine)	Prescription skin patch worn behind the ear; tablets in some countries	Useful for longer passages. Can cause dry mouth, blurred vision and drowsiness; not suitable for everyone, including children and people with certain eye or prostate conditions.
Non-drowsy allergy pills	Cetirizine, loratadine, fexofenadine	Not effective for motion sickness, so don’t rely on them.

Please talk to a doctor or pharmacist before using any of these, particularly for children, older sailors, pregnant women, anyone taking other medicines, or anyone with glaucoma, heart, prostate or other health conditions. They can tell you which product suits you, how far ahead to take it and how much. It is wise to try a new medicine on a day ashore first, so you know how drowsy it makes you before you are responsible for a watch. Never combine these drugs with alcohol, and remember that a drowsy helmsman is a safety issue.

Natural Remedies: Ginger and Acupressure

Many sailors swear by ginger, in the form of ginger biscuits, crystallized ginger, ginger tea or capsules. The scientific evidence is mixed: some studies found it helped, others found little effect. It is cheap and harmless for most people, so it is worth trying, but don’t count on it for a rough passage if you know you are very susceptible.

Acupressure wristbands, which press on a point on the inner wrist, are popular too. Controlled trials have generally found them no better than placebo, although some people genuinely feel better wearing them. If they work for you, use them, alongside the practical measures below.

Other simple helps: fresh air, steady slow breathing, music, and keeping busy with a task on deck.

Best Places to Be on the Boat

Where you sit has a big effect on how you feel. The aim is to reduce the motion you experience and to let your eyes see what your inner ear is feeling.

• Stay on deck in the fresh air, ideally in the cockpit, rather than below.
• Low and near the middle. The boat moves least near its center of motion: amidships and low down. The bow is the worst place on a pitching boat.
• Watch the horizon or a fixed point on land. This gives your eyes the information they need to agree with your inner ear.
• Take the helm. Steering is one of the best cures: you are looking ahead, anticipating each wave, and your mind is busy.
• Avoid reading, phones and close work, especially below. Navigation screens and chart work are a common trigger.
• Stay upwind of fumes. Exhaust, fuel, cooking smells and the heads compartment all make nausea worse.
• If you must go below, keep trips short. If you need rest, lie down flat on your back in a bunk near the middle of the boat and close your eyes.

What to Do If You Get Seasick

Even with good preparation, it can still happen. Act on the early signs: yawning, feeling unusually quiet, a cold sweat or a headache.

1. Get on deck into fresh air and look at the horizon, or take the helm if you are able.
2. Loosen tight clothing and keep warm. Seasick people chill quickly and become clumsy.
3. Sip water or an electrolyte drink little and often, and nibble plain crackers when you can.
4. If you are going to be sick, do it over the leeward (downwind) side, with a crew member nearby, or use a bucket in the cockpit. Never lean over the rail alone at night.
5. Rest lying down if you are no longer useful on deck. Sleep often brings relief.
6. Don’t take oral tablets once you are vomiting; they won’t stay down. Ask your pharmacist in advance about other options for longer passages.

A seasick sailor is a vulnerable sailor. They are slower, weaker and more likely to fall, so make sure they wear a well-fitted life jacket (see our guide to the best life jackets for sailing) and, offshore or at night, stay clipped on with a harness and tether (see jacklines and tethers). Falls over the side while being sick at the rail are a recurring theme in real sailboat accidents and the lessons they teach.

When seasickness becomes dangerous

Prolonged vomiting leads to dehydration, which in turn makes the sickness worse. Warning signs include being unable to keep any fluid down for many hours, very little urine, confusion, dizziness or extreme weakness. On a coastal trip, head for shelter. Offshore, seek medical advice by radio or satellite phone; know how to make a Pan-Pan call on your VHF radio and who to contact for telemedical advice before you set off.

Helping Seasick Crew and Children

As skipper, you can do a lot to prevent seasickness in your crew:

• Brief new crew before departure and suggest they speak to a pharmacist if they are worried.
• Give queasy crew a job on deck: steering, trimming a sheet or keeping a lookout.
• Plan meals that are simple to prepare and easy to eat in the cockpit.
• Keep the boat comfortable: reef early, choose a course that softens the motion, and avoid beating into short, steep seas if you have the choice.
• Never make fun of a seasick person, and don’t pressure them to “push through.” Embarrassment makes them hide symptoms until they are very ill.

For children, start with short trips in calm weather, keep them on deck watching the horizon, and keep them busy with games that involve looking out rather than down at screens. Medication for children needs particular care: some motion sickness drugs are not suitable for children at all, and others can make them agitated or overly sleepy. Always ask a doctor or pharmacist first. Our tips for sailing with children cover more ways to keep young crew happy aboard.

Does Seasickness Ever Go Away?

For most people, yes. Exposure is the best long-term cure: the more time you spend on the water, the better your brain copes. Many sailors feel rough for the first day of a passage and fine after that. A small minority remain susceptible all their sailing lives and manage it with medication and good habits; they still enjoy the sport, which says a lot about why sailors love sailing.

After a long passage, you may feel the ground “rocking” for a few hours once ashore. This is normal and passes quickly. If the sensation persists for days or weeks, see a doctor.

Summary

• Seasickness comes from a mismatch between what your eyes and inner ear sense.
• Sleep well, avoid alcohol, eat light and stay hydrated before sailing.
• If you are prone to it, take medication before departure, after checking with a doctor or pharmacist.
• On board, stay on deck, low and amidships, watch the horizon and take the helm.
• Look after seasick crew: keep them warm, hydrated, in a life jacket and never alone at the rail.

This article is general information, not medical advice. For advice about medicines or health conditions, consult a doctor or pharmacist.