Normally Key West is, but not for the time you are there. Coco Cay is a private island - more exactly it is about 100 acres of sand and scrub brush that RCI owns and they have a beach day there with a couple or three bars they set up and wandering bar waiters selling "Coco Locos", which are rum drinks. Coco Cay is an extension of the ship - your cruise card is needed to buy drinks, the lunch is cooked and served by the ship's staff, etc. They do have a small native market set up with souvenirs - and this requires cash as they don't take the cruise card for payment. Nassau....probably your best choice if for no other reason than the length of time you are there.