Yes ... just as if you were on the ship. Free soda at Cookies BBQ, as well. Lunch is served from 11:30 till 2PM. Of course, if you were to order soda from a bar tender, they would charge. Same rules for alcohol - pay as you go ... use your Key to the World card - no cash accepted.
There ARE two small Bahamian shoppes on the island. I usually do not take cash. If I see something I want, I can stop back at the ship for cash.
If you want something mailed from
Castaway Cay (with Bahamas postmark), bring cash for the Castaway Cay post office - sits about 20 feet from where you debark.
MAKE SURE YOU DO THE PARASAILING, if at all possible. Throw caution to the wind (well, you know what I mean). It's a hoot!