Unlocking the Power of Ocean Digital Twins for Policy Stakeholders

The advent of digital twin technology is revolutionizing how policymakers, governments, and businesses approach ocean management, governance, and sustain ability. This paper presents a set of five policy toolkits co-designed to support the integration of the Iliad Digital Twin of the Ocean applications into strategic decision-making processes for local and regional authorities. These toolkits elaborate how offered Iliad services align with European and global policy objectives By addressing key sectors-fisheries, aquaculture, ports, water quality and pollution, and renewable energy-the toolkits provide actionable guidance for monitoring environmental compliance, enhancing intersectoral governance, and enabling scenario-based planning. The manuscript discusses the structure of each toolkit, offers an insight on the functionality of various relevant Iliad applications, focusing on the needs and use cases of policymakers. Lastly, it outlines policy implications, capacity-building needs, and pathways toward data-driven water governance across Europe.