The pirate ship had it all – from a wooden, creepy Medusa figurehead in front to the Jolly Roger flag dancing in the morning breeze and a Jack Sparrow-lookalike with braided goatee waving us on board. We sailed to watch dolphins off the coast of Tenerife, and while my three-year-old was overjoyed, I spent the two-hour ride struggling not to feed the fish flitting around our boat.

Seasickness is one of the holidaymaker’s worst enemies. According to a recent study, ship passengers rate seasickness the worst holiday discomfort. And it’s hard to avoid; British comedian Spike Milligan once said: “The only sure cure for seasickness is to sit under a tree.”

But as the summer temperature soars, many of us contemplate boat trips – from leisurely cruises to motorboat island-hopping to sailing powered by nothing more than a stiff breeze. Some will battle through the awful tummy twirls like I did; others will simply opt to stay on firm ground instead.

Seasickness is a form of motion sickness. All types of motion sickness, be it physical such as car, sea, or air sickness, or visual, such as simulator sickness or cyber-sickness, share the same kind of  mechanism. Motion sickness occurs when the inner ear (also called the labyrinth) and central nervous system no longer know where the vertical plane is. Or in other words, when the sense of balance and equilibrium gets disturbed in your inner ear by motion, such as the swell of the sea.

The big difference is that seasickness is often prolonged. “Even the worst journeys by bus, car or plane don’t endure for days. There may be a bumpy patch on a plane, but again, there is a time limit,” says Richard Dawood, a travel medicine specialist at London’s Fleet Street Clinic.  When you’re in a car you can stop and get out. In open sea, no such luck. You may feel trapped, and this worry is yet another factor making you more likely to succumb to seasickness.

Today, many mariners experience it to various degrees, usually for the first two to three days of almost every trip

Even famous sailors, including Admiral Nelson, Charles Darwin, and Christopher Columbus, were afflicted. When the English ships of Queen Elizabeth I faced the Spanish Armada in 1588, the Spanish admiral, the Duke of Medina Sidonia, succumbed to seasickness. It’s been cited as one of the factors that led to England’s victory. In Roman times, Horace wrote of seasickness as a social leveller, as it affects both wealthy and poor.

Today, many mariners experience it to various degrees, usually for the first two to three days of almost every trip, according to Beth Leonard, an experienced sailor herself. Most get used to it after three days, regardless of what they try and do to lessen it. Leonard surveyed 38 seasoned cruisers and found that three-quarters of them got seasick on nearly every passage. Another survey by Yachting World, of 223 people who took part in the Global Challenge race, found that 62% suffered seasickness.

And it’s not just about feeling sick to the stomach. Seasickness symptoms are usually progressive, starting with yawning, salivation, cold sweat, dizziness, headache, and fatigue, and culminating with nausea and possibly vomiting. During the first few days at sea, many people also report problems concentrating. Leonard found that 33% of those surveyed experienced drowsiness, a quarter reported feeling lethargic, a whopping 79% had nausea, and half vomited. If early warning signs were ignored, 86% of sufferers experienced increasingly severe symptoms, ending with repeated vomiting.

But experienced sailors often have their own tricks to get through seasickness as quickly as possible. Sebastian Smith is one of them. Together with his wife Adele and two small daughters, he loves long sailing trips, and has written books and blog posts on sailing and dealing with the motion sickness that comes with it.

“I’ve never been able to understand why there are such variations between people,” he says. “Seasickness has nothing to do with age or strength, apparently. It also can come on quite suddenly. People may be having a good time, looking relaxed, and you see the change in their face all of a sudden. Ten minutes later they’re in the foetal position.”

Smith says he suffered horribly at first, but once he started sailing long distances, he simply got over it and it hasn’t returned. “There is definitely a psychological side to it, in my own experience. I now know that even if I get the first twinges, I will get over them and get through it. That’s experience and experience counts,” he says.

Smith says that for some, the best way to tackle seasickness is to simply sleep it off.

His wife Adele still gets seasick on the first day or two of a long trip. Their children didn’t suffer at all when they were babies – “and, curiously, nor did Adele, even if you’d imagine dealing with nappies in a tiny, bouncing, airless cabin at sea would be the ultimate guarantee.” After they were toddlers, the kids would get seasick, but they now get over it – every time. “It may take three days and a lot of vomiting but then it suddenly stops and they are as hearty as the toughest old salt.”

Smith says that for some, the best way to tackle seasickness is to simply sleep it off. The cabin is often the place where movement is at its weakest  – so even if the wind makes you feel better, don’t be scared of taking a nap in the cabin.

Not all can manage it, though, and many people must rely on medication, such as Stugeron or Dramamine. But try any medication ashore first, cautions Smith, as some are powerful sedatives.

Dawood says that for prolonged duration of action – up to three days – the first medication to try should be a Scopoderm skin patch (though the patches do have side effects, and should always be prescribed by a doctor or travel clinic). “Discuss the problem carefully with your doctor: for severe vomiting, another prescription medicine (Ondansetron) is highly effective, and is absorbed directly under the tongue without needing to be swallowed.”

But when you take your medication also matters. One of the sailors surveyed by Leonard, Andrew Burton, used to run the Adventure Sailing program, regularly taking a fleet of sailing boats between Bermuda and the Caribbean.

Smith advises to avoid alcohol for at least a couple of days before the trip

Once, he had nine boats with 54 crewmembers, and the team was stuck for three days in Newport because of bad weather. Thinking that they’d be off the next day, Burton told people each evening to take their seasick medication – and when they finally left, amidst breeze and big waves, only one person got seasick – the one who didn’t take any medication at all. Seasoned sailors suggest you take seasickness medication not a few hours before travel, but much earlier, at least the night before.

Another tip is not to step on a ship with a hangover. Smith advises to avoid alcohol for at least a couple of days before the trip. When you do start feeling funny, keep munching, he says, especially when you think you can’t. Dry crackers, plain fruit and raw vegetables are especially good; some people swear by ginger biscuits and ginger tea. “And, for some reason, oranges,” adds Smith.

It’s also best to avoid for three days before anything that has ever given you indigestion, such as spices, grease, caffeine, salt, or sugar.

If you do feel the urge to vomit and you’re on a high-speed sailing boat, don’t lean over the side as you may fall overboard. Use a bucket or a biodegradable bag (like those used by dog owners) instead. And vomiting causes dehydration, so drink plenty to replace lost fluids.

One of the sailors quizzed by Leonard advised people to prepare as much as possible before the trip – such as preparing meals that are easy on the stomach for the first five days.

Sesickness can be exacerbated by strong smells like diesel oil, being too hot or too cold, and eye strain from reading or working on a computer. Listening to music or an audiobook don’t create the same problems.

Looking at the horizon can also help. And on deck, try to keep your balance while standing free, says Jelte Bos, a kinesiology expert at the Vrije Universiteit in Amsterdam, as that will stimulate your central nervous system to adapt as quickly as possible. Finally, he says, if you feel the symptoms, drink some fizzy cola.

Swell generally moves the whole ship up and down, and continuously changes its speed

If you’re planning a holiday of a lifetime on a large cruise ship, though, you probably will be OK, even without ginger beer: seasickness seldom strikes on stable, large cruise ships, where the motion is usually barely detectable.

Your nausea may also, surprisingly, depend on the shape of the boat. A recent project funded by the EU called Compass, also called “A Rational Approach for Reduction of Motion Sickness & Improvement of Passenger Comfort and Safety in Sea Transportation,” looked at different types of ships and at how the most important three accelerations (longitudinal or fore-aft, lateral or left-right, and vertical or up-down) impacted seasickness. Compass found that both horizontal and vertical accelerations contribute to seasickness on board, meaning that seasickness is three times less on a passenger ship with a catamaran configuration, compared with a single-hulled vessel.

Acceleration is a prerequisite for feeling motion and for getting sick from motion – and aboard a ship, swell generally moves the whole ship up and down, and continuously changes its speed. The resulting vertical acceleration is a dominant factor that causes seasickness, says Bos. “When, in addition, you are located above the point about which a ship rotates, you will be moved both laterally and longitudinally, and these motions will thus cause horizontal accelerations that will cause sickness too,” he adds. The amount the ship rolls from left to right can also be a factor.

Ship’s motions can be calculated from its design and, given specific waves environment, this offers the possibility to predict how bad sickness will be on board – even before a ship is built. In general, catamarans show less roll motion than monohulls, just because they are wider, says Bos. Catamarans, however, are generally shorter than monohulls, meaning they rotate more about their vertical axis than monohulls. “Because generally the latter effect is less than the former, catamarans can be more comfortable with respect to seasickness than monohulls,” he says.

If large cruise ships are not your thing and you like to stick to rowing or sailing on inland waterways, you’ll probably be fine, says Bos. “Humans are typically most sensitive for cyclic motion varying with a period of about six seconds. Small boats sailed on inland waterways generally show motions with smaller periods to which we are substantially less susceptible.” The closer you are to those trees Spike Milligan suggested you sit under, the less likely you are to be ill.

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