The combination of surfing and psychological interventions is not new, and several projects have demonstrated outcomes such as increased psychosocial well-being, hope, and mental health. Mindfulness strategies have been identified as key tools that can enhance the impact of sea-based programs on well-being. Combining these strategies with socioemotional learning (SEL) can further strengthen the effectiveness of such interventions. Considering the role of self-determination theory, particularly its motivational components such as basic psychological needs (BPNs), in intervention programs and their outcomes, this study sought to analyze the effects of a surf therapy program incorporating mindfulness strategies on the promotion of socioemotional skills, BPNs satisfaction, and the reduction of psychological distress. Nineteen youths, aged between 12 and 19 (M = 14.63, SD = 2.24), previously identified with symptoms of depression and anxiety, participated in this study. A quasi-experimental design was employed, with two assessment points (i.e., pre- and post-intervention), and a 15-session intervention combining surfing, mindfulness, and SEL was developed. Results indicated increases in all mean scores for socioemotional competences, as well as for competence and relatedness (BPN satisfaction), with statistically significant improvements observed in self-awareness and decision-making. Levels of depression and stress decreased, while anxiety showed a slight increase, although none of these changes were statistically significant. The intervention demonstrated a positive impact on the development of socioemotional skills, particularly those related to mindfulness. This study highlights how surf therapy can be a vehicle for meaningful changes in mindfulness, while also emphasizing a significant need for further analysis into the role of motivation in shaping emotion regulation and well-being in these kinds of interventions.