Those cruise ships are so big and have stabalizers to dampen any motion,
Even when we hit real heavy seas 2 years ago , they were coming over the bow, the ship didn't pitch very much.
Usually this time of year the sea is so flat that that there isn't any motion at all.
For some unknown reason I haven't had a problem with sea sickness on smaller boats in swells or choppy water but it's hard for me to even look at carnival rides without getting queasy.
A larger ship with a cabin near mid ship will be even easier.