Usually the way sea sickness works is you'll be sick for a few days, once you get used to the motion of the ship it will subside and you'll be alright. The only problem is when you're in port for extended periods of times, you start all over again. I wouldn't worry about it too much. If you can do competitive sailing and deal with it, you're not going to have too much trouble on the ship, except perhaps the lack of horizon. Just remember, lowest deck, leeward side.
Oh, the patches are great I hear, however, you might escape the mocking if you just pop the pills. Either way Penguin Gal said it best, don't worry about it now. In the words of Ted Kennedy "we'll drive off that bridge when we get there"
