The U.S. Coast Guard and other government agencies broadcast different kinds of maritime safety warnings, using a variety of different radio systems to ensure coverage of different ocean areas for which the United States has responsibility, and ensure all ships of every size and nationality can receive this safety information. All broadcasts except those over VHF and MF radiotelephone are made by computer.
Coastal Maritime Safety Broadcasts
VHF Marine Radio Broadcasts. Urgent marine navigational and weather information is broadcast over VHF channel 22A (157.1 MHZ) from over 200 sites covering the coastal areas of the U.S., including the Great Lakes, major inland waterways, Puerto Rico, Alaska, Hawaii and Guam. Broadcasts are first announced over the distress, safety and calling channel 16 before they are made. All ships in U.S. waters over 20m in length are required to monitor VHF channel 16, and must have radios capable of tuning to the VHF simplex channel 22A.
NOAA Weather Radio (NWR) is a nationwide network of radio stations broadcasting continuous weather information direct from a nearby National Weather Service office. NWR broadcasts National Weather Service warnings, watches, forecasts and other hazard information 24 hours a day. In addition, you may visit the NOAA/NWS Marine Product Dissemination Information web page (USCG broadcast schedules for VHF, MF, HF, NAVTEX, and HF NBDP (radio telex) are included here) or obtain NGA Broadcast Warnings.
High Seas Broadcasts
Worldwide Navigational and Meteorological safety broadcasts are organized by NAVAREAS and METAREAs, which can be selected by Inmarsat C SafetyNET equipment. Listings of international NAVTEX and HF narrowband direct printing broadcast schedules are included in the IMO Master Plan of Shore-based Facilities for the GMDSS.
Weather forecasts and warnings are broadcast over scheduled HF radiotelephone channels from Coast Guard Communication Stations using a very distinctive and recognizable computer-synthesized voice.
For information concerning other U.S. and international marine radiofacsimile broadcasts, see HF-Fax Schedules.
Marine Radiofacsimile Policy: The Coast Guard, which broadcasts radio facsimile information from five Communications Stations, will continue these broadcasts to meet the needs of its cutters, and to meet public safety needs as described in Chapter V of the Safety of Life at Sea Convention, unless otherwise directed.
HF Radiotelex (HF SITOR). Weather, NAVAREA and other navigational safety text information, recognized by the GMDSS, are broadcast over scheduled GMDSS HF narrow-band direct printing channels from Coast Guard Communications Stations.
The U.S. National Weather Service has a new World Wide Web page listing sources and schedules for receiving marine meteorological information by a variety of means, including Internet, radio, satellite, computer bulletin board, and others.
Even with satellites, meteorologists cannot accurately prepare marine weather forecasts without accurate ship weather reports. For this reason, the National Weather Service sponsors the United States Voluntary Observing Ship Program (VOS). Ships participating in the VOS program provide meteorological and oceanographic reports while at sea. These observations form the basis of marine weather forecasts in coastal and high seas areas. For more information, see the NWS Port Meteorological Officers and Voluntary Observing Ship Program Page.