Whatever you decide to take, continue taking them a few days after your cruise ends. I do not suffer motion sickness, and was fine during even the choppy parts of our cruise. (The waves just lulled me to sleep.) BUT, when we returned, I was on land about 5 hours when I was hit with motion sickness. HUH?! Apparently, I still had my "sea legs", so everything spinned and I became very nauseous. It took a few days to return to normal, and I've read that this happens to people. Have a great cruise, and take your pills!