Descend 15 feet beneath the sea to the Undersea Observatory and view the ever changing life on a natural coral reef. At mid-level, visit the Deep Reef Tank and, from the top level enjoy spectacular views of the St. Thomas shoreline and neighboring islands.

From the Undersea Observatory, you have a unique opportunity to stay dry and watch totally non-captive fish and other marine creatures as they go about their daily activities on the reef completely unaware of your presence. The scene changes frequently because the marine life here is free to come and go at will. You never know what might swim by – today a barracuda, tomorrow a turtle. Watch large schools of horse-eye jacks suspended in the current. Sometimes the tower is surrounded by huge schools of silversides. During the twice daily feedings, watch hundreds of fish engulf our diver outside the observation windows.

Or perhaps you would like to turn things around and be out there with the fish looking in. Then sign up for Sea Trek, the ultimate helmet dive. You can make your reservation at the kiosk on the top level of the Tower.

The Deep Reef Tank at mid-level (currently being renovated) contains a variety of schooling fish, sharks, tarpon and other large fish found in deeper waters.

The top level of the Tower is home to our reservations desk for all the Activities at Coral World. In addition to spectacular island views at this level, from December through March, you may get lucky and see a humpback whale and her calf breaching or tail or flipper slapping in the passage between the Tower and Thatch Cay. Humpback whales migrate to the Caribbean in the fall to breed and calve. In the winter, they begin their migration back to colder waters where they will gorge themselves during the summer.

Whales do not eat when they are in the Caribbean. They live off reserves of fat called blubber built up during the summer in the North Atlantic.

Fish school as protection against enemies because it is easier for a predator to capture a fish swimming alone than to cut out a single fish from a huge group.

Silversides are several species of minnow-sized bait fish that include anchovies, herring and sardines. They often form huge bait balls on which pelicans and larger fish love to feed.