Long Range Certificate Course

Details of NAVTEX CRS may be found in ALRS Volume 5 and ITU List of Coast Stations and Special Service Stations (List-IV)

WWNWS comprises 3 levels of warning:

• NAVAREA warnings: are issued by a NAVAREA coordinator and include information required by ocean-going mariners for safe navigation. They are principally affecting main shipping routes and offshore areas within GMDSS Sea Area A3, so they are not broadcast via the NAVTEX system but via satellite and/or HF NBDP. Within GMDSS Sea Areas A4, these are not broadcast via NAVTEX system but only via HF NBDP.
  
• COASTAL warnings: are also issued by a national coordinator and include information required by all vessels for safe navigation within the given area. They are affecting areas up to 400 NM from a NAVTEX CRS but within the boundary agreed with adjacent national coordinator.
• LOCAL warnings: are issued by a local coordinator; for example a port or harbour authority. They include information required for safe navigation within port or inshore waters that passing ocean-going vessels do not require.

For meteorological warnings each NAVAREA is sub-divided into METAREAs' METAREAs are usually divided into sea areas for weather forecast broadcast using INMARSAT-C (EGC), NAVTEX, VHF, MF/SSB and HF/SSB radio. In principle a sea area should not straddle two or more METAREAs and those names of sea areas should, as far as possible relate to well known geographical locations or areas. Some countries (e.g. Italy) still use their own names for their sea area when using local NAVTEX, VHF or MF.