Scenarios can help individuals, communities, corporations and nations to develop a capacity for dealing with the unknown and unpredictable, or the unlikely but possible. A range of scientific methods for developing scenarios is available, but we argue that they have limited capacity to investigate complex social-ecological futures because: 1) non-linear change is rarely incorporated and: 2) they rarely involve co-evolutionary dynamics of integrated social-ecological systems. This manuscript intends to address these two concerns by applying the method of science fiction prototyping to developing scenarios for the future of global fisheries in a changing global ocean. We used an empirically informed background on existing and emerging trends in marine natural resource use and dynamics to develop four 'radical ocean futures,' incorporating and extrapolating from existing environmental, technological, social and economic trends. We argue that the distinctive method as applied here can complement existing scenario methodologies and assist scientists in developing a holistic understanding of complex systems dynamics. The approach holds promise for making scenarios more accessible and interesting to non-academics and can be useful for developing proactive governance mechanisms.