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GMDSS
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Maritime Information:
INSTRUCTIONS FOR CANCELING A FALSE DISTRESS ALERT

Effective 01 August, 2013, the U. S. Coast Guard terminated its radio guard of the international voice distress, safety and calling frequency 2182 kHz and the international digital selective calling (DSC) distress and safety frequency 2187.5 kHz. Additionally, marine information and weather broadcasts transmitted on 2670 kHz will terminate concurrently. See the safety alert. Note that these frequencies are still available and in use, notwithstanding the Coast Guard's termination of the radio guard. Please contact us if you have any questions.


Digital Selective Calling

*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.
1 VHF
  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 DSC number, and cancel the false distress alert.

Example:

All Stations, All Stations, All Stations

This is NAME, CALL SIGN,

DSC NUMBER, POSITION.

Cancel my distress alert of

DATE, TIME UTC,

= Master NAME, CALL SIGN,

DSC NUMBER, DATE, TIME UTC.

2 MF
  1. switch off equipment immediately**;
  2. switch equipment on and tune for radiotelephony transmission on 2,182 kHz; and
  3. make broadcast to "All Stations" giving the ship's name, call sign and DSC number, and cancel the false distress alert.

Example

All Stations, All Stations, All Stations

This is NAME, CALL SIGN,

DSC NUMBER, POSITION.

Cancel my distress alert of

DATE, TIME UTC,

= Master NAME, CALL SIGN,

DSC NUMBER, DATE, TIME UTC.

3 HF

As for MF, but the alert must be cancelled on all the frequency bands on which it was transmitted. Hence, in stage 2.2 the transmitter should be tuned consecutively to the radiotelephony distress frequencies in the 4, 6, 8, 12 and 16 MHz bands, as necessary.

Other Distress Systems

4 Inmarsat-C

Notify the appropriate RCC to cancel the alert by sending a distress priority message via the same CES through which the false distress alert was sent.

Example of message

NAME, CALL SIGN, IDENTITY NUMBER,

POSITION,

Cancel my Inmarsat-C distress

alert of DATE, TIME UTC

= Master +

5 EPIRBs

If for any reason an EPIRB is activated accidentally, the ship should contact the nearest coast station or an appropriate coast earth station or RCC and cancel the distress alert.

6 General
  1. Notwithstanding the above, ships may use any means available to them to inform the appropriate authorities that a false distress alert has been transmitted and should be cancelled.
  2. No action will normally be taken against any ship or mariner for reporting and cancelling a false distress alert. However, in view of the serious consequences of false alerts, and the strict ban on their transmission, Governments may prosecute in cases of repeated violations.
Adapted from International Maritime Organization (IMO) Resolution A.814(19)