Garmin 190-01098-00 Manuel D’Utilisation

Digital Selective Calling

Digital Selective Calling (DSC) is a key component of the Global Maritime Distress and 

Safety System (GMDSS). DSC provides VHF radios with the ability to place and receive 

digital calls directly with other vessels and shore stations, including the USA and Canadian 

Coast Guards. Your radio includes full Class D DSC capabilities.
If you have a GPS device connected to the transceiver, your latitude and longitude and the 

current time are transmitted when you send a distress call or other type of DSC call. If you 

have manually entered your position information, your latitude, longitude, and time of entry 

are transmitted with the call. Having your location automatically transmitted prevents you 

from needing to identify your location in an emergency situation.
Channel 70 is reserved exclusively for DSC calls, and your radio uses a dedicated receiver 

to maintain a constant watch on Channel 70. You do not need to change the channel to make 

a DSC call, since your radio automatically changes to Channel 70 to transmit a DSC call. 

Your radio sends the DSC data over Channel 70 in less than one second, and then tunes to 

the appropriate channel for voice communications. The   icon is displayed when you 

have an incoming or missed DSC call.
IMPORTANT: To use the DSC capabilities of your radio, you must first enter a Mobile 

Maritime Safety Identity (MMSI) number. An MMSI number identifies each DSC radio, 

like a telephone number.
IMPORTANT: The radio disables DSC if you turn on ATIS. See 

The Mobile Maritime Safety Identity (MMSI) number is a nine-digit code that acts as a 

DSC self-identification number, and is required in order to use the DSC capabilities of your 

radio. You can obtain an MMSI number from the telecommunications authority or ship 

registry for your country. In the USA, you can obtain an MMSI number from the following 

sources:

Federal Communications Commission (FCC)—assignments are recognized 

internationally
BoatU.S., Sea Tow, or United States Power Squadrons

®

—assignments are for USA 

waters only

After obtaining your MMSI number, you must program the number into your radio to 

enable DSC.

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