Actually, the saltines work because they help to absorb the acid in your stomach, not because they have any other naturopathic substance. Plus, if they don't completely work, puking something is better than dry heaving and it will help rid your stomach of the acid.
On that note, avoid foods that could possibly give you an acid stomach, greasy stuff, coffee, OJ, etc.
If you are going to take seasickness meds like Bonine or Dramamine, start the night before or at least six hours before you go out. It is not effective is you are taking it just as the symptoms are starting to appear or as Ber said the box says, one hour before.
Scopalamine works, but don't overdo it! One is more than enough. In fact, a half a patch might even be enough for you. The coach of the UH sailing team once told me a story of taking his mainland parents on a Molokai Channel crossing. Halfway thru the trip, his Dad starts totally wigging out! They didn't know what was wrong with him until they realized he had a Scopalamine patch on each side of his neck! Apparently, he had heard so many horror stories about the crossing that he felt one was good, two must be even better!
I don't usally get seasick myself. On this subject, you never say never though! It happens sometimes even to folks with the cast iron stomachs. However, I have the Navy man/dive instructor husband who will feed the fish every time out without meds. I also own a sailboat, so I've done a lot of research to keep him happy when we go out!
It also helps to stay in the center of the boat (less motion), away from the diesel fumes, do what you can to keep your body temp regulated, and focus on the horizon (ever notice that hardly anyone gets motion sick when they drive?).
