|Most people (90%) are prone to seasickness. I am one of those. Even though I was practically born on a boat and spent my entire childhood on a boat, I still get seasick.
Seasickness is caused by the brain's attempt to integrate signals coming from the body, eyes and inner ear as part of our balance system. Frequently, the eyes are reporting things as stable that are not, such as a bulkhead, rail, deck or some other object while the inner ear insists that everything is in motion. While the body will eventually adjust to a sustained level of motion, the period of adjustment might be as long as two weeks. Most would prefer to die rather than suffer two weeks of seasickness. Even more frustrating is that others around may feel no effects whatsoever. Your tolerance of a given level of motion will increase with repeated or prolonged exposure, but that is no guarantee that a higher level of motion will not bring on the symptoms again.
Sleepiness can often be the first sign and some people who think they don't get seasick actually do without realizing it. People who love to take a nap the moment they get out onto the water are probably feeling the effects of mild motion sickness.
After sleepiness comes the nausea but it is often mild and may not be much of a problem. Studies have shown that maintaining a positive state of mind can help offset the effects.
For many unfortunate souls the symptoms escalate to extreme nausea, vomiting, dizziness, headache, pallor and cold perspiration.
For kayakers who must maintain balance to keep their vessel right side up, dizziness can be a very bad condition, so seasickness is a very serious concern for us.
To reduce chances of becoming seasick, try to not think about it too much. Concentration on how you are feeling will make it worse. Try to keep your peripheral vision on the horizon. Staring at a fixed point will not help. The actual steadiness of the horizon can help reduce seasickness, but in a kayak that is so low to the water, the horizon will be hidden by swell of any appreciable size. Detailed work, looking through a pair of binoculars or referring to a compass, can bring on symptoms quickly.
If you are susceptible to seasickness, there are several options for you if you act far enough in advance. Once you get seasick, there is not much that will help but time or getting to some place still.
There are several medicines that will fight seasickness. Two of these are Marazine and Dramamine. Both are effective but can make you groggy and lethargic. They must be taken as a series starting at least 24 hours in advance of their being needed.
Scopalamine which is delivered by a transdermal patch behind the ear must also be started one day ahead of being needed. I have used it before but found that the patch is easily washed off by spray or floated off by sweat. I was able to keep it on only by covering it with a patch of duct tape. It was effective I guess as I did not get seasick.
All these medicines are very powerful and have some side effects. You should refer to the label for each of these.
One natural remedy that has been very effective is to chew ginger during your ordeal. The root ginger stores very well and is nearly impervious to wet conditions. You can easily bite off another chunk from a piece stashed in a deck bag or even a pocket. More pleasant to eat is candied ginger which is ginger and sugar in gel. It does dissolve when wet however.
Olives and lemons are said to delay onset of sea sickness by preventing the production of excessive saliva. They are not convenient for use in a kayak however.
Some claim effectiveness for various bands that apply pressure to the wrist or behind the ear. I have not found these to be effective. Neither did the staff of the Myth Busterstelevision show.