Well, I had only one problem ever until this cruise. The waters were really choppy but I was doing OK until dinner. The dining room was warm; we were being served too much food and the tomatoes and garlic put me over the top. When I returned to the cabin laying in the bed didn't help as I was rocking in the bed in the same direction as the ship was rocking. I got up and lay down perpendicular to the floor and then I went to sleep. I was fine the next day. The Baltic capitals were absolutely gorgeous.
Also, I am told that it is not wise to look at the horizon. And you're right, keep moving. If I hadn't gone to dinner and had I gone dancing, I would have been OK.