Module 6 - Distress & Mayday
False Distress Alert Cancellation
What you will learn
Cancel an inadvertently transmitted VHF DSC distress alert promptly using the current WRC-23 sequence instead of switching the set off and hoping the alert disappears.
A false alert is an emergency workload for rescue services until it is cancelled. The current ITU procedure combines the radio's own instructions or self-cancel capability with a Channel 16 all-stations voice cancellation containing the vessel identity and UTC alert time.
ITU Resolution 349 (Rev.WRC-23) says to follow the radio-screen instructions where applicable, or switch off and on after ten seconds and then follow the screen instructions where applicable. If the DSC equipment can transmit a distress self-cancel, start that operation according to the current equipment procedure. Do not stop at resetting the set.
Set Channel 16 and transmit a broadcast to ALL STATIONS. Give ALL STATIONS three times, THIS IS, the vessel name three times, call sign or other identification, MMSI, and the words PLEASE CANCEL MY DISTRESS ALERT OF followed by the alert time in UTC. Keep listening and answer any Coastguard or station response.
Use additional appropriate means to tell the responsible authority that the alert was false and has been cancelled. Report promptly and honestly. The ITU resolution says no action will normally be taken for reporting and cancelling, while repeated violations may attract action because false alerts consume rescue resources and can obstruct real distress traffic.
| Step | Action | Failure prevented |
|---|---|---|
| 1 | Follow the display, or reset after ten seconds as the current procedure specifies | Leaves the set ready to show applicable cancellation instructions |
| 2 | Use distress self-cancel if the equipment supports it | Cancels through the DSC capability where available |
| 3 | Select Channel 16 | Moves to the VHF distress voice channel |
| 4 | Broadcast vessel name, call sign, MMSI and UTC alert time to ALL STATIONS | Lets listeners match the cancellation to the false alert |
| 5 | Use additional appropriate contact and maintain the watch | Confirms the responsible authority has the corrected status |
Turn an accidental press into an accountable cancellation
A crew member inadvertently completes the protected distress-button hold and the set confirms that an alert has transmitted at 1426 UTC.
1. Do not hide it
Note 1426 UTC, follow the equipment display and initiate self-cancel if the set supports it.
2. Cancel by voice
Select Channel 16 and make the all-stations cancellation with the vessel name, call sign, MMSI and 1426 UTC.
3. Confirm the correction
Maintain the watch, respond to the Coastguard and use another appropriate contact route if needed.
Sense check: The cancellation must identify exactly which vessel and UTC alert are being cancelled; 'sorry, false alarm' alone is not enough.
Common mistake or limitation
- Switching the radio off and leaving it off without making the required cancellation.
- Omitting the MMSI or UTC alert time, so the cancellation cannot be matched reliably.
- Delaying because of embarrassment while rescue organisations continue responding.
Recap
- Follow the current equipment instructions and use self-cancel where supported.
- Make the Channel 16 all-stations voice cancellation with identity and UTC alert time.
- Maintain the watch and confirm the responsible authority has the correction.
Optional quick check
Section 10 of 10
Which information uniquely anchors the voice cancellation?
Sources and factual review
Reviewed 1 September 2026 - Compass Revision editorial review.
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