Ian Waugh - A Mariner\'s Guide to Marine Communications

(John Hannent) #1
Many Coast Stations broadcasting Weather/Navigational Warnings do not
preceed the voice broadcast with a DSC Alert. Admiralty List of Radio

Signals, Volume 3 (ALRS Vo13) provides a world-wide list of Coast


Stations broadcasting weather and navigation warnings. ALRS Vol. 3 also
includes Weather/Navigation Warning maps, showing the forecast areas/

Nav warning areas for many of the stations listed. (See Chapter 2 -


Maritime Safety Information)

Example - VesselJustinalGJUS has suffered engine failure,


which the engineer 'Scotty' expects to be able to fix without


outside help within a few hours. Weather and other


conditions are such that the vessel is not in danger, but the


master wants other vessels to know that they are not under


command and to ask that they keep clear.


Ch70 DSC Safety Alert addressed to All Stations, showing Ch16 for
subsequent voice communications.
Ch 16 'Securite, Securite, Securite, All Stations, All Stations, All
Stations.
This is Justina, Justina, Justina - Golf Juliet Uniform Sierra -
MMSI 232456789.
Navigation Warning 25/1200UTC. Position 51 30N 001 23£ -
lost main engine power and unable to manoeuvre expected
duration three hours no assistance required - vessels in the
area please keep a wide berth - Out'.


Channel 16 was free of Distress/Urgency traffic, allowing it to be


used for the voice 'Securite' Call and Message. Justina included her MMSI
in the voice broadcast, to let other vessels match the voice message with the
DSC Alert.justina did not want other vessels to reply, hence 'Out' at the
end of the message.
The message was given a reference 'Navigation Warning date/ time
VTC' so that it could be cancelled without causing confusion. If a Coast
Station/MRCC has acknowledged the original message, Justina should
ask that Coast Station to acknowledge the cancellation message, e.g:


Ch70 DSC All Stations Safety Alert, showing Ch16 for subsequent
voice communications.
Ch16 'Securite, Securite, Securite, All Stations, All Stations All
Stations,


MARINE COMMUNICATIONS 123
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