When we cruised last year, I asked our pediatrician about what to give. He said he would wait and see if the kids got sick, and then, take them to the ships doc. Well, I decided that I was not spending $4000 to watch my keds barf. So, I gave each child (7 and 10) a 1/2 a Bonine at bedtime. That way, if it did make them sleepy, most of the effects would be while they were sleeping. Was that the safe, smart thing to do????????? Probably not, but it worked.......and I'll do it again this trip.