You could always rent a car and explore the island on your own if you'd like a day filled w/several experiences and doing it on your own time line. There's one major road around the island and beach clubs are easy to access (all along the same side of the island, only a few miles apart from one another). You could then venture to the East side where things are far less developed...more rugged coastline, beautiful views! Grab lunch at Bite on the Beach as you start your way back to San Miguel. You could also tour the Mayan Ruins at San Gervasio (also along the way back to San Miguel)...I think admission was $6 each. Drop the rental car off and still have time to do a little shopping in town b/4 getting on the ship.