What is an “Alert”?

An “Alert” is a digital text message that sends information between radios. It is the big difference between newer DSC radios and older non-DSC radios.

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

Different types of Alert

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 alert 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 alert 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 alert or All Ships Safety alert 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 is used and the process for sending them on our Icom radios:


Terms we use

Alert – 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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