International biodiversity commitments will remain largely aspirational unless they are translated into socially legitimate forms of local action. This challenge is particularly evident in marine protected areas (MPAs), where conservation objectives intersect with fisheries, tourism, energy development, local livelihoods, and competing uses of marine space. Addressing these tensions requires ecological knowledge as well as stakeholder dialogue and an understanding of biodiversity governance as both a scientific and socio-political process. This paper presents <em>Protecting</em> <em>Blue</em> <em>Horizons</em>, a role-play exercise designed to help students and young adults explore how global biodiversity goals can be negotiated in local MPA contexts. The exercise combines top-down policy objectives with bottom-up stakeholder deliberation. Eleven stakeholder roles were developed through interviews, literature review, and professional experience. Particular attention is given to moderation and to the debriefing as components of reflection and learning. The role-play was tested in different educational settings. An initial implementation with young adults included debriefing and provided formative feedback on moderation and consensus building. Subsequent university implementations in Argentina and Mexico used shorter formats and constituted the analytical corpus of this study. As these sessions did not include formal debriefing, the analysis focused on recorded stakeholder deliberations. Directed thematic content analysis used the four overarching goals of the Kunming–Montreal Global Biodiversity Framework (GBF) as analytical categories. Goal B, concerning sustainable use and nature’s contributions to people, was most consistently represented, while Goals A and D were partially represented and Goal C, concerning fair benefit-sharing, was least represented. The findings suggest that <em>Protecting Blue Horizons</em> can support engagement with biodiversity governance while highlighting dimensions that require more explicit integration into scenario design, facilitation, and debriefing. The role-play is proposed as a flexible educational tool for strengthening deliberative skills and more grounded engagement with GBF implementation.