The blue economy is a major driver of urban and regional development, creating millions of local jobs in water-dependent sectors such as fisheries, tourism, and shipping. However, it can also contribute to carbon emissions and ecosystem degradation, while its reliance on freshwater, coastal and marine ecosystems exposes it to the impacts of climate change. As the places where the blue economy takes place, creates value and provides jobs, cities and regions play a key role in unlocking the potential of a resilient blue economy that preserves the ecosystems that sustain it. Building on a global survey of 80+ cities, regions and basins, this report highlights the costs and benefits of the blue economy at subnational level, shedding light on the link between the blue economy and water security. This analysis provides an overview of the multi-level governance of the blue economy and related gaps. It calls on cities and regions to develop resilient, inclusive, sustainable and circular (RISC-proof) blue economies by establishing the right governance conditions related to policy making, policy coherence and policy implementation. The report concludes with a RISC Assessment Framework that offers a self-evaluation tool for subnational governments.