Multi-use (mu), is defined as an intentional jo...multi-use (mu), is defined as an intentional joint use of ocean space and resources by two or more users in close geographic proximity. it represents a radical change from the concept of exclusive resource rights to the inclusive sharing of resources by one or more uses. the concept is gaining popularity in recent years as a concept that can contribute to a more sustainable use of ocean resources and is advocated by eu policy (eu msp directive, blue growth strategy) and research programmes (fp 7 and horizon 2020). ocean multi-use (mu) can reduce spatial pressures, create new opportunities for socio-economic developments and have environmental benefits, but currently there is not much knowledge available on its impacts. existing approaches for managing marine space and assessing impacts are also still focused on single-use planning. mu is also supported by private foundations (e.g. somos project by lloyd’s foundation), maritime spatial planning (msp) processes (e.g. in portugal, belgium, bulgaria) and policy frameworks advocating for more efficient and sustainable use of resources (e.g. in the netherlands). nevertheless, the implementation of ocean mu is still limited, due to low level of certainty about its impacts and low confidence of regulators to support, and investors to venture, in to such novel approaches. multi-frame project gathers a multi-disciplinary partnership from 7 countries, in four continents. the partnership brings exceptionally strong expertise in ocean planning and mu systems, and is highly skilled in using innovative collaboration techniques (e.g. participatory mapping, scenario development). multi-frame encourages the increased and sustainable application of the ocean multi-use (mu) concept to ultimately contribute to a more efficient and sustainable use of ocean resources. the specific objectives of multi-frame include: 1. develop, test and optimize a generic assessment approach for sustainable ocean multi-use 2. systems, focusing on vulnerable areas; 3. highlight best practices and concrete tools for developing ocean mu systems; 4. promote knowledge-exchange and new forms of cooperation between ocean actors; 5. encourage the uptake of mu by worldwide ocean planners, researchers, policymakers, industry and 6. society-at-large 7. promote mu’s contribution to spatial efficiency with a focus on innovation and true sustainability encompassing social, economic, and environmental pilars. the multi-frame research framework provides the processes and methods needed to develop, implement, and assess the sustainability of mu efforts across a range of geographic, environmental, and institutional contexts. the framework has 6 work packages, including 5 unique case studies, which will allow common challenges and potential solutions to be explored to ensure credible, insightful results to enable broad utility.