What is an “Alert” or “Announcement”?

An “Alert” or “Announcement” is a digital text message that sends information between radios. All alerts and announcements include the MMSI number which identifies the boat. It is the big difference between newer DSC radios and older non-DSC radios.

Note: alerts and announcements are almost the same. The word alert is reserved for the “distress alert” which is a digital message send before the distress (mayday) message. A distress alert also includes the boats position and is the one alert sent by pressing the two “distress” button. 

The advantage of sending an alert or announcement is that if you are calling another vessel you don’t need to know which channel the they are on.

Different types of Alerts or Announcements

In the case of a routine call using DSC when you are one other vessel, as long as you know their MMSI number you can send an routine announcement to them. This sounds an alarm at their end regardless of the channel they are on. See the DSC Call page for more information.

A similar process is used if you send a group announcement where an alarm will sound on all vessels within range with the group MMSI programmed into the radio. See the Group Call page for more information.

In the the case of a Distress alert, All Ships Urgency announcement or All Ships Safety announcement if you sent these alert an alarm will sound on every vessel fitting with a DSC radio within range.

The table below show when each of these alerts or announcements is used and the process for sending them on our Icom radios.

Note: You should not send any alert or announcement before a Mayday Relay message (this was changed in 2019).

Terms we use

Alert or Announcements – The digital part of the message (as above).

– The initial voice message used to invite a reply (ie. Clubhouse, Clubhouse, this is Deepsea, Over)

– The information that you are trying to send (ie. Where do you want this racing mark laid?)


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