The Blue Economy, which incorporates all economic activities related to oceans, seas, and coastal areas, is vital to the sustainable development of regions across the globe. The Black Sea, located at the crossroads of Europe and Asia, has enormous potential for the growth of a prosperous Blue Economy. This potential is, however, accompanied by a unique set of challenges that must be addressed to assure the sustainable growth of maritime industries in the region. These problems are addressed by DOORS Black Sea ( https://www.doorsblacksea.eu ), an EU-funded project that develops optimal and open Black Sea research support. DOORS connects residents, research, and industry to regenerate the Black Sea and create “blue economy” prospects by establishing a system of systems (SoS) to address human and climate change impacts on the marine ecosystem. DOORS’ success, value, and effect depend on stakeholder engagement. They progress science and technology with researchers, making project work more meaningful. Multi-actor Forums (MAFs) bring together national stakeholders from Romania, Bulgaria, Turkey, and Georgia of all backgrounds to help scientists prioritize Black Sea issues with a focus on blue economy policies and innovations to fill gaps. This method also helps co-design the region's System of Systems to give researchers the datasets they need to solve environmental problems and grow the blue economy. This study analyzes how findings may affect the long-term expansion of the Blue Economy and related policy in the region.