The horizons of mobile satellite communications have been expanding with ever-increasing speed, and there are several different options for the design and capability of new services. The adoption by the IMO Assembly of Resolution A.1001(25) – Criteria for the Provision of Mobile Satellite Communication Systems in the Global Maritime Distress and Safety System (GMDSS), provided a clear indication of IMO’s intention to consider opening up provision of GMDSS services to any satellite operator whose system fits these Criteria. Expansion of the market is most likely to happen in the context of a revision of Chapter IV (Radiocommunications) of the Safety of Live at Sea (SOLAS) Convention and will provide the opportunity for specifying more effective services in a way that permits the use of evolutionary capabilities and non-geostationary satellite constellations. At present, Inmarsat, with the satellite communications system which it operates, is the sole global provider of these services, although, after the restructuring of Inmarsat, the process of liberalization and privatization of global and regional satellite communications services is fast developing. IMSO is currently conducting the assessment of the application in relation to the provision of GMDSS by Iridium