Don't eat any heavy and/or greasy brekkies. Bring/eat some ginger snap cookies or go to Beachy's place and get some real ginger. Eat some ginger before and while heading out on the boat.
Also, keep your eye on the horizon and not on the up and down of the sea.
Do eat (some say don't eat at all) but just have something like a pear and a piece of cheese (and a ginger snap).
