How Sea Sickness Occurs in the Sea Sick Passenger

Seasickness is a particularly debilitating form of motion sickness. Motion sickness occurs as a result of the brain acting on conflicting signals from the inner ear and eyes.

Not all boat trips are calm like this channel crossing
Not all boat trips are calm like this channel crossing

All boats, even big cruise liners and ferries will move in relation to fixed references such as the horizon or coast line, potentially causing this conflict. The confusion in the brain is further complicated by items we would normally expect to stay in one place, such as walls and furniture, also moving in relation to the fixed reference points.

The motion of a boat rolling or corkscrewing will often cause more distress for the sea sickness sufferer, and is particular worse when the boat is moving slowly and in smaller boats such as sailing yachts, dinghies and fishing boats. In our busy waters dropping anchor for a spot of relaxed sea fishing can end in the fishing boat being rocked from side to side from the wake from passing boats causing sea sickness in both new and experienced sea anglers.

Where there is a conflict between inner ear and eye signals, the brain will believe the inner ear as the eyes can be fooled into seeing things that aren’t there as our illusion demonstrates.

The brain determines that this conflict is due to hallucination by poisoning and the area postrema part of the brain responds by inducing vomiting to remove toxins from the body. Vomiting doesn’t improve the situation, so the cycle continues until either the brain becomes used to the different signals it is receiving, you get back on shore or you fool the brain that you are on dry land - we’ve got some tips on this coming up.

Quite why some people always suffer from sea sickness and others never suffer from it remains a mystery. If you suffer, or your children suffer making any sort of boat trip a nightmare you have our sympathy.

As we sell sick bags, we would love you to buy some Chuckie Bags right now, after all it’s better to have a discrete bag to be sick in. Nevertheless we would much rather you didn’t need them. We’ve been sea sick and had children turn various shades of green on the cross channel ferry, so we know how horrid it is. So we’ve put together some tips on the next page on preventing sea sickness and some natural remedies that might help if seasickness sets in.