PART 4 - Canadian Coast Guard

False Distress Alerts and Distress Relay Alerts
The GMDSS has been in force for ships on international voyages since February 1, 1999, following its seven-year phasein.
During this time, considerable experience was gained internationally in the operation of the GMDSS. While the
GMDSS has proven its overall effectiveness, the high number of accidental distress alert activations and the inappropriate
and unintended Digital Selective Calling (DSC) distress relay alerts have detracted from the efficiency of the system.
Excessive false alerts and distress relay alerts can create an unnecessary burden and workload for SAR services. They may
also cause confusion and undermine mariner’s confidence in the GMDSS. They could potentially have a serious impact on
real distress situations.
With the aim of minimizing the number of false alerts and distress alert relays, the following information is provided:
• “Instructions for Mariners and Others on How to Cancel a False Alert” (appendix to IMO Resolution A.814(19)
entitled Guidelines for the Avoidance of False Distress Alerts)
• “Procedure for Responding to DSC Distress Alerts by Ships” (COMSAR/Cir.21)
DSC
Instructions for Mariners and Others* on How to Cancel a False Distress Alert
[Appendix to IMO Resolution A.814 (19)]
1 VHF
2 MF
1. switch off transmitter immediately**;
2. switch equipment on and set to Channel 16; and
3. make broadcast to "All Stations" giving the ship's name, call sign and MMSI number, and cancel the false
distress alert.
Example
All Stations, All Stations, All Stations
This is NAME, CALL SIGN,
MMSI NUMBER, POSITION.
Cancel my distress alert of
DATE, TIME UTC,
= Master NAME, CALL SIGN,
MMSI NUMBER, DATE, TIME UTC
1. switch off equipment immediately**;
2. switch equipment on and tune for radiotelephony transmission on 2182 kHz; and
3. make broadcast to "All Stations" giving the ship's name, call sign and MMSI number, and cancel the false
distress alert.
Example
All Stations, All Stations, All Stations
This is NAME, CALL SIGN,
MMSI NUMBER, POSITION.
Cancel my distress alert of
DATE, TIME UTC,
= Master NAME, CALL SIGN,
MMSI NUMBER, DATE, TIME UTC
* Appropriate signals should precede these messages in accordance with the ITU Radio Regulations Chapter NIX.
** This applies when the false alert is detected during transmission.
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