The main purpose of the “Manual for Use by the Maritime Mobile and Maritime Mobile- Satellite Services” is to provide the maritime community with a description of the GMDSS and other maritime operational procedures. It also provides mariners with a compilation of the most relevant ITU treaty, regulatory, technical and operational texts that are relevant to the maritime mobile and maritime mobile-satellite services, so that the concerned persons could have ready reference to these texts in the application of the relevant radiocommunication procedures. The requirement for providing ship stations with the Maritime Manual was introduced into the Radio Regulations in 1979 following an earlier requirement, dating back to 1927, for providing the Radio Regulations and the Convention, onboard ship. The Manual for use by the Maritime Mobile and Maritime Mobile-Satellite Services is published in accordance with Article 20 (No. 20.14) of the Radio Regulations. It provides descriptive text of the organisation and operation of the GMDSS and other maritime operational procedures and contains extracts of the regulatory texts associated with maritime operations.