They say bonine is less sleep-inducing than the other stuff. There was a dramamine "less drowsy" formula but I think it was pulled from the market. Of course, the downside to OTC meds is you have to take them before the symptoms strike or it is probably not going to work.
There are as many cures for motion sickness as there are for the hiccups. Ginger and apples work for some. Getting to a place where you can see the horizon works for some. For others, eating crackers works. Salty food does seem to help me on the rare occasions I get queasy - and everyone is susceptible to getting sea sick, even a grizzled old sea dog like a ship's captain. I prefer to not use medications.
If it strikes you badly, the ship's doctor has a magic injection (promethazine)that works like a charm - of course it will cost you and probably put you to sleep.
The biggest help is to not fret about it. Your itinerary is in waters that are usually very calm. This as opposed to getting out in the Gulf Of Alaska, where a highly experienced cruiser friend once told me he encountered the worst seas he'd ever seen.