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Courtesy of the United States Coast Guard

The U.S. Coast Guard broadcasts National Weather Service highseas forecasts and storm warnings from four high seas communication stations in the SITOR (SImplex Teletype Over Radio) mode. These broadcasts are prepared cooperatively by the Marine Prediction Center, Tropical Prediction Center and Honolulu Forecast Office. Offshore and coastal forecasts are available in areas such as Alaska. The International Ice Patrol also broadcasts from Boston sharing the same transmitters.

The table below lists station locations and schedules. Transmission range is dependent upon operating frequency, time of day and atmospheric conditions and can vary from only short distances to several thousand miles.

U.S. Coast Guard SITOR text broadcasts are performed in FEC/SITOR mode B and is also known as Narrow Band Direct Printing (NBDP). SITOR/NBDP is an automated direct printing service similar to NAVTEX, but does not offer all of the same functionality such as avoiding repeated messages. In the U.S., SITOR/NBDP is not approved as an alternative to NAVTEX or SafetyNET for fulfilling the Marine Safety Information (MSI) requirement of ships required to be GMDSS (Global Maritime Distress and Safety System) equipped.

Coast Guard HF SITOR (NBDP) Broadcast Schedule Boston, Massachusetts (NMF): 6314 (0000Z, 0100Z), 8416.5, 12579 and 16806.5 (1200Z, 1600Z) kHz Start Broadcast 0140Z 1630Z Ice (Seasonal, ~Feb-Sep) 0030Z3 1218Z3 Point Reyes, California (NMC): 8416.5 and 16806.5 kHz Start Broadcast 0005Z 1800Z Honolulu, Hawaii (NMO): 8416.5, 12579 and 22376 kHz Start (8/12/22 MHz) 0130Z 1730Z2 2030Z 2230Z1 Start (8/12 MHz) 0330Z2 0430Z 0630Z 1 0730Z 1330Z Guam (NRV): 12579, 16806.5 and 22376 kHz Start Broadcast 0230Z1 0500Z 0900Z1 1500Z 1900Z 2315Z 1 HYDROPAC navigation message, no weather 2 NAVAREA navigation message, no weather 3 International Ice Patrol, call letters NIK

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