The World Ocean Assessment - or, to give its full title, The First Global Integrated Marine Assessment - is the outcome of the first cycle of the United Nations' Regular Process for Global Reporting and Assessment of the State of the Marine Environment, including Socioeconomic Aspects. The Assessment provides vital, scientifically-grounded bases for the consideration of ocean issues, including climate change, by governments, intergovernmental agencies, non-governmental agencies and all other stakeholders and policymakers involved in ocean affairs. Together with future assessments and related initiatives, it will support the implementation of the recently adopted 2030 Agenda for Sustainable Development, particularly its ocean-related goals. Moreover, it will also form an important reference text for marine science courses.