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DSC/VHF and MMSI Numbers

If you’re a new boater -- or even if you’ve been boating for years, you’ve probably noticed how many new features are available among today’s available selection of marine radios. It can be a little overwhelming --and far too complicated! There is one feature, however, that strives to be as simple as possible – and that’s called Digital Selective Calling – or DSC. Today, we’re going to look at the proper use of the DSC radio, and how this feature could help save your life by taking the “search” out of “search and rescue!”

First, what is Digital Selective Calling and what are its benefits? DSC is a digital transfer between radios – as opposed to traditional “voice only” radios. This service allows mariners to instantly send an automatically formatted distress alert to the Coast Guard. The Rescue 21 system -- currently being deployed in stages across the country -- allows the Coast Guard to receive these digital transmissions.


 

So, why is it necessary to use the DSC technology? In case of emergency, when you press the ‘distress’ button, DSC will relay vital information to the Coast Guard – information like the name and description of your boat, your location – IF you’ve got your DSC connected to a GPS -- date and time of distress, emergency contact information, and even the nature of distress if you have entered it. This reduces the period of time it takes the Coast Guard to reach you.

It’s simple to use. Even a first-time guest on your boat can signal for help should a crisis occur.

Here’s how DSC works.

Let’s say you’re out on the water for a relaxing day of sightseeing, when an emergency occurs. It could be a fire, a flood, or a medical emergency. You need assistance and you need it fast! In order to summon help, turn to your DSC radio. On the front of the radio you’ll see a “distress” button. Press the button. That’s where Digital Selective Calling and Rescue 21 take over.

Once you press the distress button, your radio sends a digital signal over Channel 70 to the Coast Guard, as well as to other boats within range that have DSC radios. Your radio will continue to send this distress call until someone acknowledges it. The message is fast – only one third of a second – and it’s accurate, complete and automatically recorded.

When a boater pushes the button on a DSC equipped radio, it’ll send us a text message into our common center via our rescue 21 communications system. It will pop up an alert on there letting us know that there’s a new digital selective calling distress that came in.

Now if that vessels’ registered their mmsi number and it’s hooked into their gps system it’ll tell us that there’s a distress, the latitude, longitude position of that boater as well as give us their mmsi number. With that we’ll go into our databases, search for that mmsi number, which will give us the characteristics of the boat, it’ll give us the registered owner as well as his contact numbers and addresses, and then we can begin executing a search and rescue case.

Once the Coast Guard’s gotten your message, the watchstander will acknowledge your message, and your radio will automatically switch to Channel 16 in order so that you can talk to the Coast Guard. In addition, other vessels in the area will know that you are in a crisis, and will know your location, MMSI, date and time of distress.

So Rescue 21 works – and it works fast. But in order for the system to function properly, it’s vital that your DSC is set up correctly. It must be connected to your GPS using a simple one or two wire connection (check your radio and GPS manuals for exact directions!) and you must have an MMSI number.

So Rescue 21 works – and it works fast. But in order for the system to function properly, it’s vital that your DSC is set up correctly. It must be connected to your GPS using a simple one or two wire connection (check your radio and GPS manuals for exact directions!) and you must have an MMSI number.

And that’s all there is to it. Three easy steps. Connect your DSC radio to your GPS. Get an MMSI number. Enter that MMSI number into your radio. Takes maybe an hour or two of your life – and you may just have saved your own life!