Every time I write this, I get flamed hard, but it helped me tremendously, so here goes:
The best way to deal with motion sickness is to realize that it's not real. It's all in your head.
Before I went on a cruise many years ago, I visited my doctor because I, too, was worried about motion sickness, having experienced it myself during a boat ride. My doctor's advice? Try some of those magnet wristbands; they'll help.
This puzzled me greatly. My doctor was telling me to use magnets? This sounded a lot like a placebo to me. I did some extensive googling, and sure enough: most motion sickness is self-inflicted, a result of your brain's inability to reconcile sight with motion.
Some easy things to do:
At the beginning of the cruise, stand on deck in the open air and scan the horizon. See and feel how the ship is moving. Get your brain used to the sense of motion despite the apparent immobility of much of the surroundings.
Avoid other people who are sick. If you see someone else being queasy, then *you* can become queasy. It's a weird psychological thing but it's absolutely true.
Antihistamines help, although they have their own side effects like drowsiness.
Speaking for myself, once I learned it was all in my head, I got over it. Really. I forced my brain to realize that I was in a moving ship and that everything was fine. Once I did that, I didn't get nauseated.
Others will have different experiences, I'm sure.
