4 – Planning NAVTEX Services

  4.1 When planning NAVTEX services, it is strongly recommended that administrations obtain guidance at an early stage from IMO, through its NAVTEX Co-ordinating Panel. This may be particularly important when installation of new stations and/or purchase of new equipment is under consideration. Details of how to contact the Panel may be found at Annex 1.

  4.2 International NAVTEX services on 518 kHz

 When planning an International NAVTEX service it is essential to appreciate the high level of national and international co-ordination required. The central principles which should be borne in mind are as follows:

• .1 all NAVTEX stations are part of the strategic infrastructure of both the GMDSS and WWNWS.

• .2 it is essential for the efficiency and effectiveness of the service that a minimum number of stations are used. This may require national administrations to either share facilities or promulgate information provided by administrations of other nations.

• .3 each station shall contribute to the overall service in a co-ordinated way, bearing in mind the geographical area covered by each station and the effective co-ordination and control of information to be transmitted.

• .4 the two basic areas which must be defined when establishing a NAVTEX station are the NAVTEX coverage area and the NAVTEX service area. Each station will provide all the information for a particular NAVTEX service area. The boundaries of the NAVTEX service area must be wholly contained within the coverage area, and must not overlap with adjacent NAVTEX service areas (see Figure 4) .

• .5 national administrations seeking to establish NAVTEX services shall undertake preliminary discussions with the NAVAREA Co-ordinator, METAREA Issuing Services and neighbouring administrations prior to formal application to IMO through the IMO NAVTEX Co-ordinating Panel. These discussions shall consider the most appropriate NAVTEX service area boundaries, possible geographical locations for transmitter sites to ensure optimal coverage and links with Information Providers.

• .6 the range of a NAVTEX transmitter depends on the transmitted power and local radio propagation conditions. The actual range achieved shall be adjusted to the minimum required for adequate reception in the specified NAVTEX service area, taking into account the needs of ships approaching from other areas. Experience indicates that the required range of 250 to 400 nautical miles will normally be attained by transmitted power of no more than 1 kW during daylight with a 60% reduction during night conditions.

• .7 after the choice of transmitter sites, the main need for co-ordination lies in the assignment of B₁ transmitter identification characters (time schedules) and the agreement of proposed NAVTEX service areas (if appropriate). Preliminary discussions between national administrations seeking to establish or amend NAVTEX services and neighbouring administrations shall be co-ordinated by the NAVAREA Co-ordinator prior to formal application for a B₁ transmitter identification character. Throughout the process the IMO NAVTEX Co-ordinating Panel is available to advise and liaise on the final limits of NAVTEX service areas if these cannot be agreed locally.

• .8 the IMO NAVTEX Co-ordinating Panel will only allocate B₁ transmitter identification characters after the NAVTEX service areas have been agreed.

 The Baltic Sea and its approaches has been divided into four individual NAVTEX service areas. Within each service area, maritime safety information is provided from a separate NAVTEX station which has been allocated a dedicated B₁ transmitter identification character. It is a fundamental requirement that the range of each NAVTEX transmitter is sufficient to include the whole of the NAVTEX service area assigned to its B1 transmitter identification character.

• .9 once a NAVTEX transmitter has been declared operational, if a national administration wishes to:

  • a) move the transmitter site; and/or

  • b) amend the limits of its NAVTEX service area

• then the whole co-ordination process outlined above must be repeated, keeping the NAVTEX Co-ordinating Panel informed at all times.

• .10 a national NAVTEX Co-ordinator shall be established to oversee the operation of the NAVTEX services established by each national administration. The responsibilities of the NAVTEX Co-ordinator are defined in Section 12 of this Manual.

  4.3 National NAVTEX services on 490 kHz or 4209·5 kHz

 The provisions of the NAVTEX Manual apply to National NAVTEX Services on 490 kHz or 4209.5 kHz. When planning a National NAVTEX Service, the IMO NAVTEX Co-ordinating Panel is responsible for the allocation of B₁ transmitter identification characters; however, the establishment of NAVTEX service areas and the compulsory use of the English language are not required.

  4.4 National NAVTEX services on other frequencies

 The provisions of the NAVTEX manual do not apply when planning a national NAVTEX service on nationally assigned frequencies.