I brought Ginger pills with me that folks recommended to me. I never once used it. Let me ask you this though, have you ever been on a regular boat just tooling around a lake or any body of water?
If so, did you feel ill? If not...you'll probably be fine on a ship! You don't feel the motion at all. (unless rough seas are involved, then its every stomach for themselves). If you have traveled on a subway train or dealt with turbulence on a plane & you handle that with no problem - you'll be fine on the ship. Those both have more bumps!