I go to my doctor and get a prescription for the Transdermal Scopolamine patch. Ginger works a little for me and Dramamine, even the non-drowsy knocks me out for 12 hours after taking it. I love the Scop patch because you put it behind your ear a half hour before the activity and then you wear it for 3 days and then put on another one if you need to. That way you are always prepared and you don't have to worry about taking a pill at the right time.
However, that being said, there are some side effects to the patch that you should discuss with your doctor. I just experienced the dry mouth and it was very mild and only for an hour the first time I put it on.