The challenges of managing marine ecosystems for multiple users, while well recognised, has not led to clear strategies, principles or practice. The paper uses novel workshop based thought-experiments to address these concerns. These took the form of trans-disciplinary Non-Sectarian Scenario Experiments (NSSE), involving participants who agreed to put aside their disciplinary interests and commercial and institutional obligations. The NSSE form of co-production of knowledge is a distinctive addition to the participatory and scenario literatures in marine resource management (MRM). Set in the context of resource use conflicts in New Zealand, the workshops assembled diverse participants in the marine economy to co-develop and co-explore the making of socio-ecological knowledge and identify capability required for a new generation of multi-use oriented resource management. The thought-experiments assumed that non-sectarian navigation of scenarios will resource a step-change in marine management by facilitating new connections, relationships, and understandings of potential marine futures. Two questions guided workshop interactions: what science needs spring from pursuing imaginable possibilities and directions in a field of scenarios, and what kinds of institutions would aid the generation of science knowledge, and it application to policy and management solutions. The effectiveness of the thought- experiments helped identify ways of dealing with core problems in multi-use marine management, such as the urgent need to cope with ecological and socio-economic surprise, and define and address cumulative impacts. Discussion focuses on how the workshops offered fresh perspectives and insights into a number of challenges. These challenges include building relations of trust and collective organisation, showing the importance of values-means-ends pathways, developing facilitative legislation to enable initiatives, and the utility of the NSSEs in informing new governance and management directions in multi-use marine environments.