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CHAPTER 1. OVERVIEW
1.1. Genaral
NAVTEX is an abbreviation for Navigational Telex and it is a Telex-broadcasting system of the coast
stations worldwide. NAVTEX of the coast stations broadcasts not only the defined ID, but also all the
information on navigational warnings, weather warnings, SAR and other marine warnings for
navigational safety of those vessels equipped with NAVTEX Receiver in the coasts.
Consisting of a part of WWNW of GMDSS monitored by IMO and IHO, NAVTEX with ‘Narrow Band
Direct Printing’ is a receiving system on board, using NAVTEX Receiver.
NAVTEX is designed to receive all the marine safety information service made with the letter
broadcasting both in English and in Local language on International Frequency: 518KHz and on Local
Frequency: 490KHz or 4209.5KHz. The services provided are mainly divided into 3(three) categories
as follows ;
Navigational warnings such as iceberg movement-related safety.
Meteorological warnings such as typhoons and wave heights.
Search and Rescue activities by Coast Guard or Coast Station, including any urgent warnings.
1.2. Broadcasting
1.2.1. Frequencies in Use
IMO recommends that navigational warning, meteorological warnings, information on SAR and other
information be received from NAVTEX Stations and broadcast on 518KHz for English, on 490KHz or
4209.5KHz. Both 518KHz for English and 490KHz for Korean have been used since March of 1999,
but Japan uses 424KHz for their local language exceptionally.
1.2.2. Location of Coast Stations and Broadcasting Time
The location of broadcasting stations basically depends on the transmitting output and the conditions
of the electric wave in the region. The stations are normally located in the range from some 250NM to
400 NM.
In reality, the major factors that decide the service region of the broadcasting stations are
‘Broadcasting Station ID’ and ‘Broadcasting Time Plan’.
It is decided by IMO Coordination Committee. As the broadcasting time of each station is every 4
hours, set not to exceed 10 minutes, the broadcasting between the stations is not overlapped.
Chapter 7 is covering the broadcasting time of each station in neighboring countries.
