||Understanding the human benefits and pressures on ocean and coastal environments is critical to keep managing these areas in a sustainable way. Outdoor recreation in marine protected areas has been increasing over the years. The increasing popularity of marine areas presents a paradox. On one hand, people seek to recreate in unique natural coastal environments with settings that match their needs and desires, and at the same time, millions of people depend on coral reefs and their income from tourism. On the other hand, the same increased recreational attention has resulted in negative impacts on the physical and social environment. Unfortunately, the literature indicates that sandy coastal areas are naturally more vulnerable to recreation impacts due to interactions between wind, waves and sediments. This is the main reason why an effective management and monitoring of visitor use is fundamental in marine protected areas. Carrying capacity is a term that emerged within the environmental and outdoor recreation fields of study and can be used as a potential management tool. A background on social carrying capacity leads to two important terms, which are satisfaction and crowding. The primary purpose of this study is to examine the satisfaction and crowding of visitors at the Florida Keys National Marine Sanctuary. There are different variables that can influence overall satisfaction and crowding levels, this study will compare these variables across recreation users, such as snorkelers and divers, and other demographic variables in the Florida Keys National Marine Sanctuary.