Seasickness: How to Prevent It and Care for Seasick Crew and Guests

Check the marine forecast (our weather guide covers sources) and choose calmer days, sheltered routes and shorter trips for guests who get sick. Wind against current and short, steep chop are the worst. Plan a turn-around point you'll actually use.

The CDC says being short on sleep can make motion sickness worse, and that alcohol and smoking should be avoided because they increase it. A light, plain meal before leaving is a common recommendation; arriving very hungry or after a heavy, greasy breakfast tends to make things worse. Stay hydrated with water.

The CDC says motion-sickness medicine works best when taken before the motion starts; once symptoms begin, the stomach slows down and pills may not be absorbed well. Options include over-the-counter antihistamine types and a prescription skin patch.

• Ask a pharmacist or doctor which product and timing is right, especially for kids, older adults, pregnant women and anyone on other medicines or with medical conditions. Follow the label.
• The CDC notes that the newer "non-drowsy" allergy antihistamines don't work for motion sickness, so don't grab the wrong box.
• Kids need extra care. The CDC warns that over-sedating young children with antihistamines can be life-threatening, and that scopolamine (including the patch) can cause hallucinations and confusion in children and should be avoided. It suggests a test dose at home before the trip, but only with your child's doctor's advice. Never use an adult's patch or pills on a child.
• About the patch: it's prescription-only, and the CDC says it should never be cut to change the dose. MedlinePlus adds: wash your hands after handling it, use caution with water sports because it can be disorienting, and it has been linked to dangerous overheating (mostly in children and adults over 60), so remove it if body temperature rises or sweating drops and see our heat illness guide. The CDC also says scopolamine shouldn't be used by people with glaucoma or at risk of urinary retention. These are questions for the prescriber.
• Ginger, wristbands and supplements: the CDC says the evidence for diets, supplements and ginger is weak and contradictory. Some people like them; check with a pharmacist before combining any supplement with other medicines.

The most common side effect of motion-sickness medicine is drowsiness, according to the CDC. MedlinePlus advises not to drive or operate machinery after taking dimenhydrinate until you know how it affects you, and to avoid alcohol with it. Running a boat counts. If you're the skipper, test any remedy on a day you aren't operating, ask your pharmacist about less-drowsy choices, and don't take one that leaves you foggy. Operating impaired by drugs or alcohol is also illegal; see our boating-under-the-influence guide.

The bow moves the most; the CDC lists avoiding locations like the bow of a ship. On most boats, the steadiest spot is near the middle, with a clear view out. (MedlinePlus mentions the upper deck as a smoother spot on a boat; that applies to big ships and ferries. On a small boat, a flybridge or tower moves more, not less.) Facing forward helps. Stay out of closed cabins and away from the stern, where exhaust can collect.

A steady view of the horizon helps the eyes and inner ear agree, and the CDC lists it among the behavioral countermeasures that help, along with avoiding visual tasks. MedlinePlus says looking into the distance instead of reading or looking at something in the vehicle can help. Put phones, books and fishing reels with tiny line knots away until you feel settled.

The CDC mentions fresh air on the face, music and pleasant smells as useful distractions, and "controlled breathing" (slow, regular breaths at your normal resting pace), which it says appears to help in laboratory trials. Keep the person out of fumes from fuel and exhaust.

The CDC notes that drivers and pilots get sick less than passengers, and that a sense of control matters. If it's safe and you're right there, let a queasy guest take the wheel on a steady course while watching the horizon. Standing and riding the motion with bent knees (getting "sea legs") also helps some people, the CDC says.

Slow down in a chop, take waves at a comfortable angle, and avoid repeated tight turns or sitting stopped and wallowing beam-to (side-on) to the waves. On boats that have them, trim tabs and gyro stabilizers can reduce motion; see our guides for their care.

• Life jacket on and someone holding onto them if they lean over the side. Use the downwind (leeward) side, away from the propeller and exhaust, or hand them a bucket in the cockpit.
• Let them lie down or sit with eyes closed or on the horizon in fresh air, near the middle of the boat. The CDC lists lying down and reassurance as supportive steps.
• Small sips of water and, later, plain crackers or bread. The CDC stresses keeping up fluids and electrolytes if someone is vomiting.
• Keep them out of the sun and watch for heat illness; dehydration and heat make each other worse. Our heat guide covers the signs.
• Don't leave a seasick person alone below deck.

Head in and get medical help if someone:

• Can't keep any fluids down for a long time, stops urinating, or becomes very weak or dizzy (dehydration)
• Has symptoms that started near the stern, in a cabin, or while a generator ran (possible CO)
• Has severe headache, chest pain, trouble breathing, confusion or fainting: 911 or VHF 16
• Is a small child, older adult, pregnant, or has a medical condition and is getting worse

The CDC says a feeling of rocking or imbalance after coming ashore is normal, rarely involves nausea and usually fades within a few hours. If it lasts for days or weeks, see a doctor. Take care on docks and ladders right after a trip, especially older guests.