This study examines domestic and international travel to the Great Barrier Reef in order to estimate the benefits the reef provides to the 2 million visitors each year. The study explores the problems of functional form and of measuring travel cost for international visits: comparing actual costs, distance, and lowest price fares. The best estimates of the annual recreational benefits of the Great Barrier Reef range between USD 700 million to 1.6 billion. The domestic value to Australia is about USD 400 million, but the estimated value to more distant countries depends on the definition of travel cost and the functional form. The study conclusively demonstrates that there are very high benefits associated with protecting high quality coral reefs.