Silva, S.F. and Ferreira, J.C., 2013. Beach Carrying Capacity: The physical and social analysis at Costa de Caparica, PortugalThe bathing-tourism phenomenon on Costa de Caparica beaches has evolved into mass tourism, compromising environmental preservation and socioeconomic balance. The aim of the study focuses on the use of management tools, such as carrying capacity, expanding to associated surfing activity in the water, as surfers are also users. This tool operates in available surface area and utilization rates, and it is also strongly influenced by the interconnection of analysis methodologies under protection of areas of higher sensitivity, and within the recreational conflict and behavioral response of users. For physical carrying capacity a head-count of users (surfers and beachgoers) was made at two different Costa de Caparica beaches, assessing their spatial distribution. After that, conflicts were analysed and sand dunes' vulnerability were studied. Finally, through GIS, areas of use were delimited and by utilization rates the advisable maximum number of users for each area was obtained. Social carrying capacity was conducted through 322 personal interviews, looking at coastal perception and beach usage. The observations made during the summer months showed that user rates were 26m2 and 54m2 per use on the sand area and, 250m2 and 660m2 per user on the water plane for surfers. The comparison of physical and social carrying capacity showed an overcrowding phenomenon, which translated into a degree of discomfort for users, especially for surfers. This paper explores the physical dimension of the beaches and the perception of users, and the need to integrate the water plane as a part of the beach carrying capacity into the beach plans.