The "Autoridade Marítima Nacional" (National Maritime Authority) or AMN is the branch of the Portuguese Navy responsible for its coast guard role. The function of AMN is performed by the Chief of Staff of the Navy himself, supported in this role by the Directorate of the Maritime Authority, which includes the Maritime Police, the Lifeguard Institute, the Lighthouse Department and the several harbourmasters. Besides the specific assets of the Directorate of Maritime Authority entirely dedicated to the coast guard role, the AMN also has at its disposal the other Portuguese Navy's assets that can be used both for military and public service missions.