What causes seasickness - and what to do about it.
For generations, experts have generally agreed on the cause of motion sickness as: "An affliction that arises from a sensory conflict between the eyes and inner ear which triggers a guttural reaction," 

When this happens, and the motion sensors in our inner ear perceive that something is out of whack, we can suffer symptoms that include nausea, drowsiness and yawning, mild headache, dry mouth, clamminess, perspiration and paleness.

A newer theory centres on a person's postural activity, or their body sway. Thomas Stoffregen, a kinesiology professor at the University of Minnesota, published research in 2013 that shows seasickness happens more frequently and to a greater degree in people whose bodies sway more - albeit, a tiny, imperceptible movement - even on land. 

More recently, he has turned his attention to how and why motion sickness affects the sexes differently. (He said women are twice as likely as men to vomit on ships.)

We also know that pregnant women are more susceptible, and kids 2 to 12 are most vulnerable. The lucky ones grow out of it, although smooth sailing for them might feel like rough seas for those who still suffer as adults. 

For those prone to seasickness, don't forget to reserve a window cabin toward the centre of the ship, which moves around less than cabins too far fore or aft.

If you know you have a tendency to suffer on the seas, it's best to take preventive measures - ideally before you embark.

One of the most effective medications is the prescription scopolamine patch, which lasts three days. Like many nausea drugs, it can cause drowsiness, blurriness and other side effects. 

Cruise ships typically dispense over-the-counter antihistamines such as meclizine and dimenhydrinate without charge at the medical clinic or reception desk.

If you want to avoid the side effects of medication, head for the alternative aisle, where you'll find acupressure wristbands, magnet bracelets and aromatherapy, which some people find effective. 

Prevention is worth "999 times more than any treatment," 

Once you're feeling symptoms, you're often past the point of no return.  Ginger stands alone as the only thing scientifically proved to help alleviate nausea from seasickness without drowsiness

Get yourself some ginger candy, ginger chews, ginger snaps, and have some ginger in your stomach before you head to sea. Nobody knows why it works, but it works.

Some sailors use pilot bread - a thick, crackerlike item similar to Colonial-era hardtack, which doesn't go stale - to settle their stomachs. 

Starting on the day before you depart, drink lots of water, get enough sleep and avoid heavy meals, alcohol and caffeine. Continue this regimen until you acclimate, which can take several hours to a week.

If your eyes are seeing what your ears are feeling, you're likely to have a great day at sea.

When you begin to feel woozy, go to the deck, breathe some fresh air and look out to the horizon. 

Keep your head still - a deck chair with a headrest works great. The worst thing you can do is go below to your cabin and, say, read a book.

If you're on a friend's boat during a calm stretch, ask if you can get behind the wheel.  Balance your head over your shoulders and knees, take the helm and steer. Your brain will automatically recalibrate to the movement. Even if you can't take the wheel, remembering to look at the channel ahead can make all the difference. 

Washington Post