Sea bands
Eyes on the horizon
Bandaid over your belly button so that it forms a seal. Plenty of people think this is a placebo effect, but so what if it is? Apparently there's a pressure point behind it,
Peppermint lollies
Ginger (Bundy ginger beer has real ginger. Many others are fake.)
Oh, also, don't eat any dairy 3+ hours before the trip.