NAVTEX - Navigational Telex

The reception of Maritime Safety Information (MSI ) is one of the nine functional requirements of GMDSS Equipment . The Navtex Receiver is used for this purpose it is a NBDP device operating on the frequency 518 KHZ and automatically receives MSI such as Naz & Weather warnings , Met Forecasts, Piracy Warnings, Distress etc .
The Frequency 490 KHZ is used for Regional LanguageBroadcast& 4209.5 KHZ is used for Broadcast in Tropical Regions.

Each msg begins with a start function (ZCZC ) followed by a space and four characters . ( B1, B2, B3, B4 )
B1 - Identifies the Navtex Station
B2 - The type of Message
B3 & B4 - indicates the Serial No of Msg followed by text of msg.
The msg usually ends with NNNN.

Our lovely world is divided into 16 Nav areas, with 24 stations max in each Nav area.
each Navtex Coastal Stations has 10 min transmission time allocated every 4 hours.

The Message Types Identified by B2  as given below ;-

A - Navigational Warnings
B - Meterological Warnings
C - Ice Reports.
D - Search & Rescue Info.
E - Meterological Forecasts.
G - Decca Messages.
H - Loran Messages
I - Omega Messages
J - Satnav Messages
K - Other Electronic Messages
L - Nav Warnings (Addition to A )
Z - No Message

Note - On Receipt of Messages A, B, D , L are indicated by Audible & Visual Alarms.
it is possible to silent A,B, L but not possible to silent D type of msg .