5. WORKING CHANNEL
The one who sends a DSC call can suggest a working channel for continued voice radio
communication.
NOTE: When a vessel is calling a coast station it does not suggest a working channel. The coast
station announces which radio channel to continue on.


ROUTINE COMMUNICATION WITH DSC CALL
EXAMPLE 1
A RADIO MESSAGE FOR SUOMENLINNA COAST GUARD STATION
COMPARE THE FOLLOWING TO THE EXAMPLES SENT WITHOUT DSC:
A Russian yacht Marlene is approaching the Finnish coast on its way to spend a holiday partly in
Helsinki and partly by sailing in the Finnish archipelago. According to European union laws a
foreign pleasure boat must report for passport control when she has entered the territorial waters
of one of the member states. The Marlene is a luxury yacht and is linked to GMDSS and has DSC.
It is 12.30 at Suomenlinna Coast Guard Station on a fine summer day.
The DSC at Suomenlinna starts signalling and shows the following message:
Format: SELECTIVE
Party ID: 002300005
Category ROUTINE
Telecom 1 TELEPHONY (F3E/G3E SIMPLEX)
Work channel NONE
Transmitted CH 70
NOTE: Marlene does not suggest a working channel. In communication between ship and coast
station, it is always the coast station that determines the choice of working channel.
SELECTIVE directed to a specific station only
PARTY ID 002300005 the MMSI number of Suomenlinna Coast Guard Station

The Coast Guard station sends the following acknowledgement:
Format: SELECTIVE
Party ID: 273678951
Category: ROUTINE
Telecom 1: TELEPHONY (F3E/G3E SIMPLEX)
Work Channel: 74
Transmitted: Ch 70
Party ID 273678951 = the MMSI number of Marlene
Format SELECTIVE = directed towards one station
The Coast Guard Station suggests:
Work channel 74
After this Marlene CONTINUES BY VOICE COMMUNICATION on channel 74:
Calling Finnish Coast Guard Suomenlinna, Finnish Coast Guard Suomenlinna,
This is Russian vessel Marlene, JAAA,
Russian vessel Marlene JAAA,
On VHF channel 74.
Over.
Russian Vessel Marlene JAAA,
This is Finnish Coast Guard Station
Suomenlinna,
Over.
Finnish Coast Guard station,
This is Russian yacht Marlene,
My position is: Latitude: 59° 56.9´ N Longitude : 024° 56.3´ E
I am in the approach channel passing Helsinki Lighthouse. I am proceeding to the Coast Guard
Station for passport control. REQUEST: Please give instructions to reach Suomenlinna Coast
Guard Station. Over.
Marlene,
This is Finnish Coast Guard.
INSTRUCTIONS: Proceed along the fairway. Pass
Harmaja Lighthouse and proceed along the fairway
distance 1.6 miles. Take fairway depth 9.6, course 328°.
Proceed distance 0.8 miles. You can see the information
on your starboard side.
I repeat: Proceed along the fairway. Pass Harmaja
Lighthouse and proceed along the fairway distance 1.6
miles. Take fairway depth 9.6, course 328°. Proceed
distance 0.8 miles. You can see the information on your
starboard side. Over.
Finnish Coast Guard ,
This is Marlene.

UNDERSTOOD. I will proceed along the fairway and pass Harmaja Lighthouse. I will take fairway
depth 9.6, steering course 328°. I will proceed along the fairway distance 0.8 miles ahead. I can
see information sign on starboard side. THANK YOU AND OUT.
AS YOU NOTICED THE DSC CALL REPLACES THE INITIAL VOICE COMMUNICATION CALL
AND ANSWER ON CHANNEL 16. CHANGING TO A WORK CHANNEL ALSO HAPPENED VIA
DSC.
THUS A TRADITIONAL VOICE TRANSMISSION ON CHANNEL 16 DIFFERS SLIGHTLY IN THE
INITIAL STAGE BUT RADIO PROCEDURE IS OTHERWISE THE SAME.