Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Radiance Class of Royal Caribbean cruise ships sits between the Vision Class and Voyager Class. The ships are built to Panamax form factor, allowing them to pass through the Panama Canal. A cruise ship or cruise liner is a passenger ship used for pleasure voyages, where the voyage itself and the ship''s amenities are part of the experience. Cruising has become a major part of the tourism industry, accounting for U.S.$27 billion with over 18 million passengers carried worldwide in 2010. The worlds largest cruise liner is Royal Carribean Internationals, Oasis of the Seas. The industry''s rapid growth has seen nine or more newly built ships catering to a North American clientele added every year since 2001, as well as others servicing European clientele.