Seaworld Explorer, Nassau

If you thought a ride on a glass-bottom boat was the ultimate aquatic experience, you've got to book a trip on this boat. While most of the ship is above water, the lower half is an underwater observatory, complete with air-conditioning and comfortable individual seats. While, unlike in snorkeling or diving, you can't reach out and touch the fish, you can get within inches of them. The Explorer visits popular undersea destination Sea Gardens Marine Park. It also stops by a local shark hangout or, alternatively, a 70 year-old wreck.