You might be able to also get ice at the Land & Sea Park office in Warderick Wells.

Depending on the boat you are chartering, the freezers can be pretty robust, so you can keep and maybe even make ice. When we were cruising in the Exumas on our own boat, we used bags like these: ice making bags . They are inexpensive, very portable, and super-efficient in a small or oddly shaped space.

One other thing we've done on charters is focus on beverages that don't require ice. We'd use up the cocktail stuff early, and by the end of the week drink wine and beer, which are easy to keep cold in fridge.