Don't they say the sure cure for sea sickness is standing under a tree? LOL.
Practical Sailor just published an article giving the results of a reader survey. The most highly rated drug (Stugeron forte) is not available in the US but can be ordered out of Canada. The other downside besides having to order from out of the country is that the product takes longer to work than others and you really need to start the night before departing. Also, be aware that there is a higher dose product for the treatment of blance disorders that is 5 times the recommended dose for seasickness (75mg). Despite this, the product was the most highly recommended among the many by a large margin.
Several of the products available in the US were rated as "effective" unfortunately, they left the user in no condition to stand a watch and those surveyed would not use them again or recommend them. In addition to drowsiness, several other, more worrisome side effects of Scapolamine patches have been discussed here on Sailnet, but according to PS they have the advantage of being effective even after the onset of seasickness which most other products don't.
s/v Palmetto Moon
1991 Catalina 36