Coastal spaces (including land areas and sea areas) in Japan are managed by the state or local governments, and their private use by individuals was not allowed unless contribution to public interest was ensured. Since the Designated Manager System for public facilities was established in 2003, management of an increasing number of public facilities based on the Local Autonomy Laws has been consigned to private sectors (called “designated managers”) nominated through the decisions of the local councils, rather than to public bodies based on the conventional “Management Commission System.” Regarding marinas including land areas and sea areas, we conducted a comparative analysis of their convenience, comfort, serviceability, and so forth before and after introduction of the Designated Manager System from the viewpoint of marina users to discuss how the private sector should manage coastal regions.