Tortuguero National Park located on the Caribbean coast of Costa Rica is only accessible by boat or air and attracts an average of 130,000 visitors yearly. The main activity of the park is the turtle nesting and hatching along the beaches as well as the observation of wildlife in the channel sys- tem. This makes it important to study the CO2 emitted by the tours operating in the park. To cal- culate these emissions researchers gathered data on engine type, horsepower and duration of idle while boats waited to buy tickets at the park entrance. The study found that tour operators emit- ted a minimum of 5.5 tons of CO2 per year into the atmosphere and water. It is likely that the park is more polluted than immediately evident.