Hi. Welcome to cruise chat. Well, I have only been on Princess once. I was on the Regal Princess over the summer, on a 10 day Alaska. I was in the gym usually everyday, doing the sauna/steam rooms, spa stuff. I never saw a "membership" offer to the gym for the duration of the cruise. I even went on the "Spa/Gym Tour" on the first day. They talked about lots of specials, but I am pretty sure I don't remember that. I hope for your sake I am wrong. Enjoy your Hawaii cruise. Bye, Lil' Lori