Seasickness can ruin one or several days of anyone's charter cruise and virtually anyone can be subject to it. In fact, 90% of the people have experienced motion sickness at one point in their lives. Only veterans offshore sailors can consider themselves impervious to sea sickness, although it can happen to them too.
Anyway, it is not our purpose here to get into the causes of sea sickness. Suffice it so say that it occurs when the brain receives inconsistent signals from the eyes and the inner ear for an extended period of time. Our goal here is to give some tips to deal with it when, or even better, before it happens.
Preventing Sea Sickness
Drugs, patches, etc.
Unfortunately, as of today, no drug can completely prevent or cure sea sickness in most people. Further, not everyone reacts the same way to any given drug. Therefore, one's got to try several until the right one is identified. Usually, those drugs cause some drowsiness at different levels depending on the drug.
Ear patches are also interesting because the chemical is released through the skin over several days, which minimizes the side effects.
However, what those drugs do is simply raise the threshold for sickness. It is proven that they are much more efficient when taken before experiencing any sea sickness, but they are not that effective in reversing it once started.
So, if you know you're prone to sea sickness, it is recommended you take the drug when still ashore before casting off, or in the morning, before leaving the anchorage.
After casting off, seasickness-prone people should absolutely not stay down below at all (where seasickness can happen in minutes), but out on deck, in fresh air. If for whatever reason, the person must stay down below, he/she should lay down on a bed, as close as possible to the center of the boat where the motion is quieter, and certainly not in the front where the motion is the most brutal. It will not prevent the seasickness from happening at all, but the person will be much less vulnerable to it.
Eating and Drinking
It is a well known fact that alcohol consumption is a direct trigger for seasickness. Any potential subject should avoid drinking before sailing or at least drink moderately, as far back as the night before. A hang over in the morning is a guarantee for sickness.
The same goes for eating. Avoid heavy food before sailing: a strong breakfast with sausages, eggs and bacon sprinkled with coffee and milk is a pretty good recipe for giving the whole thing back to the fish! So eat moderately and even avoid drinking too much liquid altogether. Stay with solid food, like bread, fruits, etc.
Dealing with Seasickness
Learn to identify the symptoms as early as possible
Usually the first signs are slight drowsiness and some lethargy. But for most people, the first very obvious signs come from the stomach (nauseous feeling, which the subject tends to try controlling), and from the skin (slight cold sweat). Then symptoms increase, and the face becomes paler (or even greener!). Any attempt to concentrate on a task (mental or else) will augment the sickness. The nauseous feeling eventually becomes incontrollable, and ends up in vomiting, sometimes violently.
Respond to the symptoms
Immediately upon noticing the first signs, you must do something about it. Absorb a drug, if not already done. If the person is down below, he/she should immediately come up on deck, in contact of fresh air. Once a deck, set the eye sight on the horizon and the distant waves.
Avoid reading, looking at a chart, a compass etc. This increases the sickness. More generally, any task that requires focusing on some work is a potential sea sickness trigger.
Keep your body cool
Do not stay in the sun: get in the shade and remove unnecessary layers of clothes.
Anticipate the boat motion
While looking outside, try to anticipate the motions by looking at the coming waves and adjusting the body position. Try to do this until you find a rhythm to it.
Talk to the skipper
He could either change the point of sail for a while or, even better, heave to in order to calm the boat's motion until you feel better. In any case, if you cannot keep the treshold of nausea under control, be prepared to handle some vomiting. Stay on the leeward side of the boat, if you have to vomit over board. And have someone prepare a bucket. Or use one of the sick-bags found in commercial aircrafts.
If Someone Becomes Really Sick
Vomiting will bring temporary relief to nausea. If it happens once, then fine. If the person vomits repeatedly, then he/she eventually will become dehydrated and weak. He/she should absorb a little bit of liquid and crackers or small pieces of bread, for example. Rest and lying down is also necessary as long as it lasts, with good ventilation and coolness.
In conclusion, the most important thing to remember from all this is: prevention. Because once one is really sick, it is very difficult to reverse the process.