How to send a distress message by VHF radio

17 May 2016

Being able to raise the alarm in the event of a distress situation is critical. In some cases, where sailing inshore, you might still be able to resort to calling the emergency services using your mobile phone, but the most reliable method is by way of a VHF radio transmitter.

Sending a Mayday must be authorised by the skipper, although if the skipper is incapacitated or overboard this important task may fall to you. It’s therefore important that you know the basics and it’s in the skipper’s best interests to make sure his crew know what to do in the event that he is incapacitated.

Sending a mayday is relatively simple, but it’s worth gathering a few pieces of information in the seconds before you start to speak. This will include your vessel’s position, your vessel’s name, the number of people on board and a clear understanding of what your emergency is. For example, do you have a man overboard or are you sinking? Perhaps someone has collapsed with a suspected heart attack. Collating this information in the 30 seconds before broadcast will make your transmission more efficient and speed up the rescue process. 

Of course, where time is of the essence it’d be great if you could just simply ‘push a button’ wouldn’t it? Well thankfully, now that DSC (Digital Selective Calling) exists, you can do just this. If you have a DSCVHF radio then you’ll find a small red button located under a plastic cover. Don’t confuse this with the red button that takes you directly to channel 16. 

If you have DSC simply lift the plastic cover and push the button, holding it for about 5 seconds. A menu will come up on the display asking what sort of distress message you would like to send. You can scroll through the various options to select the one that’s appropriate and then select, otherwise, just select the general mayday/distress option and a DSC alert will be broadcast automatically by your VHF. The alert will, if you have your GPS connected and switched on, send a detailed Latitude and longitude of your position, your vessel’s name and your mayday call. You may then follow this up with a standard mayday broadcast on Channel 16.

Charter vessels will have a small ‘crib sheet’ on board (usually located near the chart table). To send this mayday just press (key) the microphone and keep it keyed. Then speaking slowly and clearly start your broadcast. Make sure you keep the mike keyed throughout the broadcast and at the end unkey the mike. If you don’t do this, no-one can talk to you (or anyone else) on this channel.

The message should be broadcast on CH16 and is as follows:    
MAYDAY - MAYDAY - MAYDAY.  THIS IS ‘Vessel Name, Vessel Name, Vessel name’ MAYDAY Vessel Name.
MY POSITION IS....LAT AND LONG (Read Ship’s Position off GPS)
I HAVE .....................PERSONS ON BOARD

It is useful to let the coastguard also have your MMSI number and Call Sign but this can be done later. After all, if you have already sent a DSC alert the station will have this information and if you haven’t got DSC then you won’t have an MMSI number.

Remember, unkey the mike after broadcast, listen for a response and, if possible, keep a log of the time you sent the mayday and a log of the information transmitted and received. 

TOP TIP: Make sure you give your ship’s position and not the cursor position if reading your co-ordinates from a chart plotter!

The reality is that as long as you broadcast on CH16, make it clear you have a mayday and give your vessel’s position, you’ve started the rescue procedure. The most important thing to know is how to operate the VHF and how to read GPS position coordinates. Make sure more than just the skipper know this. He or she should also let another member of crew know how to start your engine and drop sails.

If you want to learn how to use a VHF and get your RYA VHF licence, click on the link below for an online course with Jolly Parrot. 

VHF online course

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