This paper proposes, from an ethnographic description of social organization and how it structures the local political authority, to analyze the connections between local power and public administration through the building of local authority at Aventureiro Beach, Ilha Grande, state of Rio de Janeiro. The inhabitants' political power and legitimate authority are connected to the ownership of boats and to the most successful campings. The boat owners take the role of legitimate at the negotiation with the municipality and state, looking after the inhabitants' rights, assuming a role in representing the domestic organization (families and vicinal groups) in political relations with the state.
Local Power; Environmental Conflict; Tourism; Social Change; Boats