If you snorkel at Coco Cay it is safe to bring a digital camera and leave it in your bag when not in use. Coco Cay is really an extension of the ship since it will still be just the passengers and crew. There are some RCI employees who live on the island, as well as some locals from neighboring islands who will set up some open air shops for souvenirs. For the native market you will need some cash since they don't take your cruise card. The cruise card is used for everything else on Coco Cay.