The United Nations launched in 2021 the Decade of Ocean Science for Sustainable Development which promotes a paradigm shift in the generation of ocean science. The Ocean Decade mobilizes state and non-state actors to co-design and co-deliver ocean knowledge and solutions. These actors work internationally across different institutional levels and in multiple economic sectors, and represent different parts of society, including scientists, policymakers, business and industry, educators, community groups, and citizens. This chapter captures multiplexity at work by presenting an innovative model for exploring the process of co-designing and co-delivering ocean science. The ‘International Collaboration in Ocean Science model’ integrates knowledge about actors (ocean stakeholders with asymmetric power and resources), influences (policy incentives and ocean conflicts), communication (ocean narratives and emotions), motivation (norms, values, knowledge systems, security concerns), processes and structures (collaborative dynamics, principles, formal and informal rules, communication competences), and joint actions, outcomes and impact. For instance, the utilization of scientific knowledge in ocean policy enhances the protection of the ocean environment. In turn, these outcomes can transform ocean governance and address the current multidimensional ocean risk landscape. The model can be used as a tool to evaluate the enabling and constraining conditions in international collaboration in ocean science. The chapter provides researchers with questions and prompt to guide their analysis.