Try boat bands. They are little wrist bans with a small plastic bead that fit snugly on your wrists. Using a theory similar to acupressure, the beads "hit the spot" that helps alleviate motion sickness. Also, NEVER eat anything with tomatoes in it the night before you go sailing. There''s something in the acid that triggers the motion sickness reaction like no other acidic food I know.
Happy sailing, and welcome to the sport/lifestyle!