If his motion sickness is as bad as I remember him describing, Dramamine may not do the trick.
Plus the key to all of these motion sickness drugs is to take them about 1/2 - 1 hour prior to setting foot on the boat. Dramamine will make you drowsy, and I wouldn't drive early in the AM while taking that stuff.
They also have magnetic bracelets, and bandaid type patches you can buy that you are suppose to put them on pressure points or something and prevent motion sickness. I saw a bunch of people wearing them when i went on a cruise last year