What Kev said and most of what AKKings said.

Take 1 Bonine the night before.
Take 1 Bonine the morning of.
The morning of eat some very plain food (bagels, dry toast, saltine crackers etc).

This routine allows your body time to acclimate to the drugs (less sleepy) and gives your stomach something to do rather than slosh liquids around until you puke.

Bring water and other food to eat. Stay away from the fumes, get fresh air and watch the horizon. Do all this stuff especially if starting the feel sick. Eating a little more of the plain food every once in awhile will settle your stomach.

After being on the water for awhile you will probably get your sea legs and you can enjoy catching other people's limits and drinking their beer (because they are sick).