If you do that then you will pay 3% on it. I would get travelers checks for the amount to gamble and cash then before you go into the casino. What do you do when you go to casinos's and stay for a few days? Do you trust their safe in the room if so then you can trust the ships safe in the room I would think. Maybe you could put a cash deposit on your sign an sale however they won't keep it separate from anything you spend like on drinks etc. I guess I really don't know the answer and just wanted to blab..
sorry I didn't help.