In 2021, the United Nations launched 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 with asymmetric power and resources to co-design and co-deliver ocean knowledge and solutions for sustainable development. These actors work across different institutional levels, in multiple economic sectors, and represent different parts of society, including scientists, policymakers, business representatives, educators, youth groups, and active citizens. The ontological security of these ocean stakeholders or participants joining in international collaboration is under-researched. This chapter argues that divergent identity needs and routines underpinning the ontological security of ocean science participants impact effective knowledge co-production and the co-design of solutions. This, in turn, complicates the collaborative process, and performance of the Ocean Decade initiative. The chapter synthesizes ontological security studies, science cooperation, and knowledge co-production to explore ‘security as being’ in international collaboration in ocean science. The next section identifies different identity needs and routines to illustrate the problem of ‘security as being’. It specifically discusses actors who are invested in: (1) the protection of maritime cultural heritage; (2) competitiveness in traditional and emerging blue economies, (3) the protection and conservation of the marine environments, (4) access to food from the oceans, and (5) the safeguarding and defense of critical maritime infrastructure.