In this paper we present the first ecological economic model of coral reefs in Hawai'i. This model contains the main elements required to assess the full picture of coral reef management and thereby enables scientists and managers to evaluate ecological and economic impacts effectively. The model is applied to two case studies, tourist overuse in Hanauma Bay, O'ahu, and algae blooms along the Kõøhei coast, Maui. The Hanauma study showed that visitors are willing to pay much more for their experience (around $10) than they are currently doing and that the net benefits of the education program (around $100 million) greatly exceed the cost of the program (around $23 million) over time. The Kõhei coast study concluded that the algae problem causes large losses of real estate value and hotel business and that mitigation could result in benefits of $30 million over time. This would justify major investments in lowering nutrient discharges in the coastal zone.