Ocean literacy is an understanding of the ocean s influence on us and our influence on the ocean. A lack of ocean literacy presents a significant obstacle for citizens to engage in environmentally sustainable behaviour, and thus is acknowledged as a complex problem that requires deliberative participation and joint-action by stakeholders across domains. The aim of the article is both to demonstrate the value of Collective Intelligence (CI) as a methodological tool to advance and enhance the promotion of environmental literacy, and to share outcomes from using the CI approach. The participatory context behind CI illustrates that working with a range of stakeholders across marine education, outreach, regulation and policy, to debate how to better promote ocean literacy among young people, improves ocean literacy and broadens society s awareness of sustainable marine environments. Findings reveal a hierarchical barrier structure localised to each country, a valuable order of echelon toward environmental change.