Step aboard Marian, a glass-bottom boat specially designed for comfort and clear viewing. On your narrated tour, discover vibrant tropical fish and amazing coral colonies, plus learn about the history and lore of the island. Marian's shallow draft takes you over the "pinnacle," where the reef comes within inches of the glass. Then travel to the "drop-off," where the ocean floor plunges 100-plus feet. Be on the lookout for dolphins or even winter humpback whales.