'Life Below Water' aims to establish how creative practice can provide an effective way to nurture self-efficacy and self-regulation in primary education. A constructionist approach was developed to help children explore UN Global Goal 14, through drawing, prototyping and storytelling as collaborative activities. Working in duets and quartets, a group of eight Key Stage 2 children were set the task of 'inventing' sea creatures with magical healing powers. The children evaluated their progress through pre and post-workshop questionnaires, and through discussions with their peers, teachers and parents. Workshop outcomes illustrate how nurturing skills in making can help foster creative agency and metacognition. Co-operating as a design team encouraged symmetrical reciprocity, self-regulation and a 'care-full' approach to environmental protection. The study provides guiding knowledge for prospective developments, based upon tentative findings. The time required to assess the impact of 'Life Below Water' is extended to enable future research efforts, by teachers and practitioners, to inform context-specific interpretations through whole-class workshops and international exchanges.