Abstract: The expansion of the blue economy requires sustainable solutions for optimizing marine resource use. The multi-use approach, increasingly integrated into Marine Spatial Planning (MSP), foster synergies between sectors such as wind energy and aquaculture. However, its implementation remains limited. This study develops a multi-use assessment framework for floating offshore wind energy and aquaculture, providing a national sectoral perspective to support MSP policy formulation through stakeholder-informed recommendations. The framework consists of three steps: i) technical suitability analysis; ii) evaluation of sectoral perceptions, and iii) SWOT analysis. By integrating technical suitability assessments-including energy production, energy evacuation, species requirements, structural survivability, and operation and maintenance-with stakeholder surveys and workshops, the framework provides a structured basis for advancing policy strategies. Technical analyses indicate significant multi-use potential within the Spanish Exclusive Economic Zone. Floating wind energy emerges as a driving activity in high-energy offshore areas, while aquaculture drives multi-use development in more sheltered zones. Stakeholders recognize economic and operational synergies, betting on the development of symbiotic multi-use in the short term. However, regulatory fragmentation, administrative barriers and environmental impact uncertainties are underscored challenges. The findings emphasize the need for coordinated regulatory frameworks and enhanced cross-sector collaboration to integrate multi-use into national maritime policies. The study provides a decision-support framework for policymakers and industry stakeholders to enhance governance and spatial planning strategies for offshore multi-use development.
