I also take the Bonine before I leave. I take it when I fly because I get migraines from flying.... so I'm ready before I board ship. Plus, with any motion sickness medication ... if you're already sick any of the pills won't help. Just an FYI... if for some reason he does get very motion sick (which shouldn't happen) the ships infirmary does have a shot for motion sickness that does work after the motion sickness has set in. Hope you have a good trip