The CLIMA access control and limitation system has been installed at the “Sea Museum” in Genoa for the safety of visitors entering to visit the S518 Nazzario Sauro submarine. The entrance is controlled by an aisi 316 stainless steel turnstile (resistant to sea corrosion) which rotates freely until the number of persons in the submarine is less than the predefined maximum number of persons. An exit turnstile automatically decreases the headcount so as to allow access to new visitors. A system of 316 stainless steel mechanical safety gates allow exit in case of fast evacuation.