The maritime environment is impacted by the frequent occurrence of events with psychotraumatic potential. Within the framework of medical assistance at sea and the coordination of maritime and land-based rescue services, the medical-psychological emergency unit (CUMP) may be called upon to intervene in situations of collective disasters involving seafarers, requiring consideration of the characteristics of this environment, whether in terms of the functioning of a crew, risk factors, or psychotraumatic manifestations in seafarers. In this context, the CUMP intervention must be adjusted to these specificities, both in terms of individual and group care, but also in terms of crisis management on a ship, with the necessary articulation with the ship's command.