Hello. This is my first message on these boards, so I apologize if I repeat anything that has been discussed before. And if I'm in the wrong section, I won't be upset if you redirect me elsewhere. I belong to a message board aimed at people who take frequent ocean cruises. One subject which keeps cropping up is that the best rooms (i.e. less rocking-and-rolling) are in the center of the ship. I've been wondering if this is a myth. It sounds logical, though. So, on my next cruise I would like to experiment by checking different decks, front and back. Finally, my question: Is there some sort of instrument which I could use to detect the relative stability or motion? Thank you, physics experts! Susan.