The menu that sent a distress alert
You are skipper of the 10.5 m motor cruiser Blue Finch, 3.5 nm south-east of St Catherine's Point, making 16 knots eastbound with four adults on board. The fixed DSC VHF was installed last month; the MMSI is programmed and the set is in normal mode. You are showing a new crew member how to store a group MMSI in the directory. While scrolling the menu you press a sequence; the set emits a long tone and the display reads 'DISTRESS ALERT SENT - WAITING FOR ACK'. You did not lift the red cover. There is no emergency: the engine is fine, the hull is sound and everyone is safe. Ch16 is quiet apart from a distant ferry exchange. The set is now showing a flashing 'ACK' symbol but no acknowledgement has arrived. The coastguard station at Bembridge is within range and monitors Ch16 and Ch70. You have a handheld VHF in the chart table. The tide is setting west at 1.5 knots.
1. What are your first actions in the 60 seconds after the display shows 'DISTRESS ALERT SENT'?
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Treat it as a live false alert, not as a menu mistake. The alert has already gone out on Ch70 with your MMSI and, if the set has a position input, your position.
First, use the set's own cancellation function if it offers one - usually a 'cancel distress' or 'false alert' option in the DSC menu. That sends a DSC cancellation on Ch70 and is the quickest way to stop the alert being treated as genuine. Do not simply press buttons at random.
Second, make a short voice announcement on Ch16 so that any station that heard the DSC alert knows it is false. For example: 'All stations, all stations, all stations. This is Blue Finch, callsign [callsign], MMSI [MMSI]. False distress alert. Cancel distress alert. Position 3.5 miles south-east of St Catherine's Point. Out.' Keep it brief and do not use the word MAYDAY.
Third, stay on Ch16 and monitor Ch70. If the coastguard acknowledges, answer immediately. The key judgement is that switching the set off at once may look like a vessel in distress that has lost power or sunk, which can escalate the response rather than cancel it.
2. The coastguard acknowledges the DSC alert and calls 'Blue Finch, Blue Finch, this is Solent Coastguard' on Ch16. Give the content of your reply and explain what you must not do.
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Answer promptly and calmly. Identify the vessel and give the facts the coastguard needs to close the incident: 'Solent Coastguard, this is Blue Finch, callsign [callsign], MMSI [MMSI]. False distress alert, no emergency. Position 3.5 miles south-east of St Catherine's Point. The alert was sent accidentally while working in the DSC menu at [time]. A DSC cancellation has been sent. All four persons on board are safe. Over.'
Then follow any instruction to repeat the cancellation or confirm details, and stay on Ch16 until the coastguard releases you.
Do not use MAYDAY or PAN PAN for a false alert; do not argue with the coastguard or blame the crew over the air; do not switch the radio off before the authority has confirmed the cancellation; and do not leave the area to 'get away' from the embarrassment. The coastguard may need to check that the alert is not a cover for a real problem, so a clear, factual account is the priority.
3. No acknowledgement appears after five minutes and the Ch16 call to the coastguard gets no reply. A crew member suggests switching the set off to 'clear the alert'. Assess that advice and state what you would do.
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Switching off is not a safe first choice. The distress alert has already reached the system; a station that then goes silent can be read as a vessel in grave danger with failed power, and search and rescue assets may be tasked. The aim is to cancel the false alert, not to hide it.
I would keep the set on, repeat the DSC cancellation if the menu allows, and keep a listening watch on Ch16. I would use the handheld on Ch16 to call the coastguard directly, and use a mobile phone to call the coastguard station if I have signal - a phone call is a perfectly good way to cancel a false DSC alert. If another vessel is within range I would ask it to relay the false-alert message. If the fixed set is clearly malfunctioning and cannot be made to cancel, I would only power it down after informing the coastguard by one of those alternative means and noting the time. I would not resume the passage without confirming the cancellation.