Sorry...but think that you are mistaken....there are no Cabanas in the retreat pool area on the Sky...they did away with those when they put cabins about the outside area of that deck.
we spent 54 days in that location on the Enchanted earlier this year, including a TA, and felt no motion. Spent 28 days on the Sky in that location last Fall, and felt no motion.
Right now, I have no idea.....it can be in different places depending on how many Plat/Elite are on board. There will be a notice of its location in your cabin....but either CLub 6 or the Vista Lounge