IMO Documents Categories IMO Conventions SAR Administration SAR Operations Medical Communications - Systems Communications - Procedures Maritime Safety Information Other Information Model Courses Various Shop Communications - Procedures Guidance Available for Purchase Please visit the IMO Bookshop. IMO Resolutions MSC.131(75) - Maintenance of a Continuous Listening Watch on VHF Channel by SOLAS Ships Whilst at Sea and Installation of VHF DSC Facilities on Non-SOLAS Ships MSC.199(80) - Adoption of Amendments to Provision of Radio Services for the Global Maritime Distress and Safety System (GMDSS)Amends Resolution A.801(19). MSC.436(99): Amendments to the International Convention for the Safety of Life at Sea, 1974, as amendedIncludes amendments to chapter IV on Radiocommunications, which incorporate the changes made to accommodate recognized mobile satellite services under GMDSS. Note that this is far from being the only Resolution amending SOLAS. A.887(21) - Establishment, Updating and Retrieval of the Information Contained in the Registration Databases for the Global Maritime Distress and Safety System (GMDSS) A954(23) - Proper Use of VHF Channels at Sea A.1001(25) - Criteria for the Provision of Mobile Satellite Communication Systems in the Global Maritime Distress and Safety System (GMDSS) IMO Circulars COMSAR-Circ.25 - Procedure for Responding to DSC Distress Alerts by Ships COMSAR/Circ.29 - Guidance for the Voluntary use of the Standardized Questionnaires and Formats for Reporting False Alerts in Collecting Data on False Alerts COMSAR/Circ.35 - Recommendations on Medium Frequency/high Frequency (MF/HF) Digital Selective Calling (DSC) Test Calls to Coast Stations COMSAR.1/Circ.45 - Guidance on Distress Alerts COMSAR.1/Circ.50/Rev.4 - Distress Priority Communications for RCCs from Shore-to-Ship Via Inmarsat COMSAR.1/Circ.56 - Guidance on Smartphone and Other Computer Device SAR Applications MSC/Circ.892 - Alerting of SAR Authorities MSC/Circ.959 - Interim Procedures for MRCCs on Receipt of Distress Alerts MSC/Circ.1078 - Guidelines to Administrations on Reporting False Alerts MSC.1/Circ.1248 - Minimizing Delays in SAR Response to Distress Alerts MSC.1/Circ.1365 - Commercially Available Locating, Tracking and Emergency Notification Devices Manage Cookie Preferences