Many ocean economic activities are not readily visible in official statistics, hindering policymakers' access to crucial information for decision making. The OECD ocean economy measurement project aims to address this by aligning ocean economy statistics with broader economic data and ensuring international consistency. This paper compares the measurement strategies of eight OECD member countries using principles from the system of national accounts. It also highlights the ocean economy thematic accounts of four countries and summarises their methods. The paper concludes with recommendations for integrating ocean economy measurements with national accounting standards, a vital step for improving the evidence base for ocean policymaking.