I bring Chimes original ginger chews, drink ginger ale and get a stateroom low deck midship. We had 30 foot waves going to Kodiak on Zaandam. Immediately went to my stateroom and was fine. Also used the chews on the way to Capri; many people and some crew were very sick, but not me thankfully.
I have used the scopolamine patch three cruises, was very sick after removal the last two times on 12 day cruises. Very bad withdrawal. I will do a trial patch at home and remove it after three days to see what happens. This is in case of really rough seas, otherwise the ginger works great for me. Good luck, motion sickness is awful!