(Reuters) — Carnival Corp (CCL) raised its annual forecast for profit, betting on strong demand and higher onboard spending as well as ticket pricing for its cruise vacations. Cruise operators, including Carnival Corp and rival Royal Caribbean Group, have been racing to offer unique and private experiences by expanding their portfolio to meet strong demand for exclusive destinations. Carnival has invested $600 million in Celebration Key, an ambitious private resort destination on Grand Bahama, to help ma ...