Seasickness is produced by the unpredictable motion of a vessel on the sea, which causes a conflict in the inner ear, which houses the human balance system. This results in symptoms such as dizziness, nausea, and vomiting. The three types of seasickness are deck sickness, ship's movement sickness, and wave-induced motion sickness. Deck sickness occurs when there is no movement at all, such as when you are on land or aboard a still vessel. People who suffer from this type of sickness feel nauseated even though they are not moving at all. It comes from an unstable platform that gives you feelings like being on a boat with no foundation. Ship's movement sickness is caused by the movement of the vehicle itself. If you are traveling by boat across open water, then you will experience this type of sickness. The most common symptom of ship's movement sickness is Dizziness, followed by Nausea and Vomiting. Wave-induced motion sickness is caused by the movement of the boat relative to the waves. If the boat is rocking back and forth, you will experience this type of sickness. The most common symptom of wave-induced motion sickness is Dizziness, followed by Nausea and Vomiting.