This technical article explains how the maritime industry is shifting from high‑GWP HFCs to low‑GWP A2L refrigerants, and what that means for shipboard refrigeration and HVAC systems. It outlines the regulatory drivers (Kigali, F‑gas, PFAS trends), the safety classification of A2Ls as “mildly flammable”, and the practical implications for system design, crew training, and equipment standards in marine environments.