As the weather warms, we can often start daydreaming about the picture-perfect summer vacation to enjoy some tropical air and soak in the sun. For many, this is the trip of a lifetime on a luxurious cruise ship sailing around the Carribean or some other exotic locale. You spend years saving and months planning the trip, only to become ill on your first day out of the harbor; spending the rest of the vacation locked in your small room, unable to enjoy all that your cruise has to offer.