Symptoms of
seasickness
At least half the crew will be seasick on a typical offshore passage. Women get seasick faster and more often than men. Seasickness usually begins with a slight headache accompanied by pale skin, dry mouth, and frequent yawning. As it worsens, there will be sweating, nausea, and vomiting. It can last up to three days and then will not occur again for at least three weeks.Preventing
seasickness
To prevent seasickness, start taking medication well beforehand—12 to 18 hours early is not too soon for some people—and then continue to take it as directed. Different meds work best for different people. The most common are meclizine tablets (Bonine, Dramamine II, Antivert) and scopolamine tablets (Scopace) or patches (Transderm Scop). Cyclizine (Marezine) is a similar antihistamine that affects the stomach rather than the nervous system. Read their precautions and experiment before setting out to evaluate any side effects, which can be severe.Limit caffeine but do not give it up because the symptoms of caffeine withdrawal mimic early symptoms of seasickness. Avoid alcohol. Eat lightly but take nothing greasy or oily. Stay hydrated. Try not to go below, and if you must, avoid engine or head smells. Stay warm and dry. Wear a hat and gloves. Face into the wind and focus far ahead, preferably while standing, well braced, with both hands free. You are most susceptible to seasickness while sitting, so if you cannot stand up, lie down flat on your back instead.
Treating
seasickness
Explaining to a victim that seasickness never killed anyone will be pointless, since death is precisely what they wish for. If they cannot arise from their berth, keep them flat on their back with eyes closed while providing warm blankets, a hat, fresh air, and plenty of liquids, but nothing with caffeine nor alcohol. Otherwise seasick crew should stay near the mast below deck, where motion is least or, preferably, above deck, but always within the cockpit and not hanging over the rail.Keep the mind occupied by standing a watch, steering, or serving as lookout. Stay in the cockpit, well away from the lifelines, and barf instead into a bucket or else brown paper bags that can go overboard. Focus on the distant shore or horizon. Take anti-nausea drugs if available—a certain illicit, smoked herb is highly effective—but be mindful of their side effects. Ginger in hard candies, soft drinks, capsules, or tea might help. It is almost certainly too late for medication by the time symptoms appear. Some swear by special wrist bands and pointing out that this works through the placebo effect would be counter-productive.
The best cure for seasickness is homemade chicken soup that you can prepare in advance and bring aboard frozen in containers.