IMO IA910M Joint IMO/IHO/WMO Manual on Maritime Safety Information (MSI Manual), 2015 Edition
This Manual provides a practical guide for anyone who is concerned with drafting navigational warnings or with the issuance of meteorological forecasts and warnings under the Global Maritime Distress and Safety System (GMDSS). Maritime Safety Information (MSI) is promulgated in accordance with the requirements of IMO resolution A.705(17), as amended. Navigational warnings are issued under the auspices of the IMO/International Hydrographic Organization (IHO) World-Wide Navigational Warning Service (WWNWS) in accordance with the requirements of IMO resolution A.706(17), as amended.
Meteorological forecasts and warnings are issued under the patronage of the World Meteorological Organization (WMO). In order to achieve the necessary impact on the mariner it is essential to present timely and relevant information in a consistent format that is clear, unambiguous and brief. Within this Manual, it is particularly intended to provide the best form of words for use in all types of navigational warnings and meteorological forecasts and warnings that are required to be broadcast in the English language. Note has been taken of the IMO Standard Marine Communication Phrases (resolution A.918(22)), where appropriate.
This Manual cannot provide specimen texts for every type of event which may occur. However, the principles illustrated herein may be applied in general to drafting messages for every kind of navigational warning and covering all types of hazards and for the issuance of meteorological forecasts and warnings.
Resolution A.706(17), as amended on the World-Wide Navigational Warning Service (MSC.1/Circ.1288), requires that "All NAVAREA, Sub-Area and coastal warnings shall be broadcast only in English in the International NAVTEX and SafetyNET services". Where this Manual has been produced in languages other than English then the message examples given in section 7 are also provided in the English language in an additional annex.