Dive Into Success: Master the SDI Open Water Scuba Diver Exam 2025 – Make Waves with Confidence!

A common cause of seasickness in divers is a change in equilibrium in the inner ear. The inner ear contains structures that help manage balance and spatial orientation. When divers are on a boat experiencing motion from waves, the fluid in the inner ear may not respond in sync with the motion perceived by the eyes. This sensory conflict can lead to symptoms of seasickness, including nausea and disorientation.

While dehydration can exacerbate feelings of nausea or illness, it is not the primary cause of seasickness. Similarly, food allergies can lead to digestive issues but are not closely related to the physical symptoms experienced during seasickness. Lack of physical fitness might affect overall endurance or comfort but does not directly cause seasickness. The mechanism behind seasickness is fundamentally linked to disturbances in the inner ear, making the second option the most appropriate choice.