Another good article from the Global Solo Challenge
Seasickness is caused by the interaction between the organs of balance, the visual and tactile systems, and the brain. While being thrown around a boat, our brain cannot reconcile the messages it receives. It is over-stimulated by conflicting information caused by the continuous acceleration and deceleration.
The result is that the brain comes to the conclusion that you have been poisoned! It therefore induces the body to vomit to get rid of the harmful substances that it imagines have been ingested. It is therefore an instinctive survival reflex, unfortunately is useless because vomiting does not solve the situation in any way.
No one is totally immune, but surely some suffer seasickness more than others. Especially different people react totally differently which is a significant risk factor when sailing with short-handed. Read on.