Take your GMDSS Course Online! GMDSS (Global Maritime Distress and Safety System) is an international system that uses advanced terrestrial and satellite technology and ship-board radio systems. This online course contains virtual simulations, developed by HALO°, for all necessary equipment including VHF radio, MF/HF radio, Inmarsat-C System, NAVTEX, EPIRB, SART and more. These simulations are threaded throughout the course to make learning simple and easy. GMDSS Certification is required for al