This will sound off base as well but the best cure for a fisherman for sea sickness is to actually catch fish, the adrenaline released actually combats the effects of sea sickness better than almost anything, however all of the advise here is spot on.
My missus suffers from the same ailment and I have been a victim of the technicolour yawn myself on occasion so best suggestion I can give you is to ask your family doctor as he can prescribe far more powerful travel medication than you can buy over the counter. An anti-emetic (nausea tablet) is usually a good thing to have on hand as well as these can be used if the travel meds have no effect.
Everyone is different and no one solution usually works for those badly affected. I was once told to suck on an oddfellows mint the entire time out and was sick the entire time (Chuck tasted better though). Ginger works for some and not others. Acupuncture works as well sometimes.
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