Marine governance is an essential way of achieving the objectives of sustainable development. It ought to be understood as the process of planning, as well as decision-making and management at the national and regional levels taking into account the global ocean as an ecological unity. The process of decision-making is closely interrelated with the regional and transnational cross-border cooperation. The adoption of the EU Directive establishing a framework for maritime spatial planning (hereinafter: MSP Directive) plays an important role in developing of marine spatial planning in Europe by promoting MSP instruments. MSP Directive requires all coastal EU Member States to prepare cross-sectoral maritime spatial plans by 2021. The development of spatial plans for Polish marine areas was started in 2013. The MSP legal bases are included in the Marine Areas of the Republic of Poland and Maritime Administration Act of 1991 amended in 2015 and its implementing regulations.