Unfortunately(as we all know), the prevention & treatments vary so much depending on susceptibility.
For chronic sufferers.....strong medication (many RX) is often the only option.
For me, I'm OK (coastal & off shore) as long as I take care of the basics #1 = sleep especially flying in for charters, proper hydration & nutrition, minimal alcohol & eliminating any anxiety (ie; preparation, crew strength). I wear the wrist bands (superstition & psychological....but I do believe
) and eating/hydrating lightly/regularly (prepared in advance) while underway. I avoid being down below especially in really rough stuff for any period of time unless sleeping.
I have used ginger snaps & ginger ale in the past...they help a little. I tested ginger chunks on a trip in May and thought they were great for anything from indigestion to that "initial feeling". The good news is that the longer the sail trip.....the thought fades from my mind until I wobble when walking on the 1st dock .
I like ginger so much now (need 12 step) on land I have tried various brands & styles.........some are sweeter (added sugar) to hotter/stronger which are my favorites.
A few recent articles:
Blue Water Sailing 8/07 - pg 19...they name histamines in the blood as a culprit
Blue Water Sailing 6/06 - pg 62
Sail - 5/05 - pg 36