When on a cruise, I got very sick from the motion.  The ship's store had sold out of the most popular motion sickness medicines.  When we stopped at the first port, San Juan, my mom called her friend who she often cruises with and had mentioned how sick I was, and she suggested Bonine.  I was able to find some in a store in San Juan.  I used it for the rest of the cruise and did not get sick again.  The taste is disgusting, but worth it.