The complex nature of sustainability challenges implies the need to provide students with interdisciplinary learning experiences and environments based on active and reflective learning. To know whether these experiences result in real learning, there must be a way of capturing and measuring the competences required to promote sustainable development using suitable indicators. This paper presents the process of building a competence map that is used as a navigation chart to monitor the sustainable education competences in the Ocean i3 experience. An action-research methodological approach is used involving participant observation, field notes, informal interviews, and documentary analysis. The participants were 38 students, 23 teachers, 3 project coordinators, and 2 researchers, and the context of the study is the five workshops carried out in the Ocean i3 project. The result is a navigation chart that traces the students’ learning journey through dialogue between the competences, learning outcomes, and activities. In conclusion, this approach to curricular planning can serve to inspire other learning environments and experiences on how to tackle the challenge of envisioning their sustainability competence development pathway. Above all, it can serve to improve competence development training schedules for sustainability.