What area of a ship would be best to book a cabin for a person with motion sickness?

Midships and as low as possible.

Dead center front to back and the lowest deck with no windows. AND the great advantage is that this is the cheapest cabin on the ship.

But if you want a cabin with a window or balcony, there's no reason to avoid that. Mid-ship offers the most stability, and on a big cruise ship it's not that much different being in a mid-ship balcony cabin and a big-ship inside cabin in terms of motion.

If you are prone to motion sickness, you need to get seabands or a prescription patch regardless. You really can't rely on cabin location since you may very well be all over the ship on sea days and will likely be in a show, a lounge, or the dining room when the ship departs in the evening.

Midship lower level, just not the lowest (not to feel the engine). And go for at least an obstructed window, not an inside.

Doug and Fmpden: people with motion sickness cannot stay in inside cabins. There is a connection between what your body feels and what your eyes see. Trust me on that

There is. My wife would agree. Thats why we can't get an aft cabin. She gets ill looking back but feeling her body move forward. Thats why a pt. on a stretcher should always be pushed with the head facing f/w.

I have always heard that it is low and in the middle. I think that if you can only get one of those options that you would want low, since i think that you feel the ship sway when you’re at the top. I just got back from a cruise to South America a couple of months ago and we were towards the front of the ship and in the middle of the height. We could feel the sway, but nothing that caused us to get sick. But everyone has different sensitivity though.