Ships today are so well stabilized that most of the time you won’t notice you are even moving! It’s a good idea though to take along some Motion Sickness precaution (follow the directions on the box) as well as aspirin and sunscreen. If you do have a problem onboard, all ships have a doctor and a nurse aboard. And be sure not to forget any prescription drugs you are taking. These should be put in your carry-on-luggage. Consult your physician before taking any medication.