I would recommend taking the ship's excursion to Blue Lagoon Island. They ferry you to an island just north of Paradise Island. It's incredible! A beautiful sheltered lagoon to swim in, things for sale, tropical drinks at a bar ($6 for a delicious Piņa Colada), hair braiding, swimming, snorkeling, hammocks, picnic tables, basketball, clean restrooms, showers, hiking, calypso music. Only drawback was the lunch prices - they were charging $8.50 for a hot dog or hamburger and $11.50 for barbecued ribs or chicken. We skipped lunch because of that. But other than that, we loved it. If you want to snorkel, they offer a swim with stingrays excursion along with it.
Cheers,
Michelle P.