NAVTEX messages are a form of SITOR transmission (digital) which relay marine 
weather and/or other important marine information for ships and boaters at 
sea.  Usually, they consist of notices to mariners regarding buoy lights 
bein5ëû extinguished, shipping channels being blocked, dredging operations, 
USN firing exercises, and a host of other useful information needed for 
sýéafe navigation.  A majority of these NAVTEX transmissions are on 518 kHz.  
That's on the upper edge of the LW band.  Happy Monitoring...Brian.
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