Bonine, Dramamine, and the wristbands, just go all out.
I did some off shore fishing near San Diego a few years back. I get wicked motion sickness, like really bad. I took the above pills and worse the acupuncture wrist bands. At a couple of points I a got a little queasy but that was it. Some other guys who claim to not get motion sickness were having to lie down on the boat to keep from throwing up.