International bodies demonstrate their commitment to the sustainability paradigm and the Education for Sustainable Development (ESD) approach through university curricula and activities that address global challenges such as poverty, inequality, and environmental degradation. The literature suggests that extracurricular activities designed from such an approach play a vital role in working towards the Sustainable Development Goals (SDGs) as they foster awareness, commitment and action. This paper explores the profile of students participating in an extracurricular ocean sustainability activity aboard the training ship Saltillo and the learning derived from it. The need arises from wanting to know some key ideas that can inspire the design and implementation of ESD-based extracurricular activities that promote the SDGs. The method consisted of a case study using e-logbooks, cover letters, Lego® Serious Play® and questionnaires as instruments. The results expose the students’ interests and academic and personal motivations to take part in the activity. Learning about sailing, sustainability, shared living, and self-awareness of their own transformation are also explored. The study offers ten tips to guide and inspire how extracurricular university activities based on the ESD approach and aimed at the SDGs can be designed.