Digital Selective Calling (DSC)Digital Selective Calling (DSC) uses marine VHF radio and GlobalPositioning System (GPS) technologies to transmit and receivelocation information. DSC is used by mariners to assist them in twomajor areas: Distress Calls and Position Reporting.A non-emergency DSC Position Report allows mariners to exchangeand display their positions. When you receive a DSC position,you can create a waypoint or to show the received position on anelectronic map.An emergency DSC Distress Call allows a vessel in troubleto transmit a substantial amount of information in a singletransmission, or “call,” without the need for voice communication.When any nearby rescuer receives the DSC signal, an alarm sounds,and they immediately receive the position of the caller.The rescuer may then choose to navigate (Go To) the caller’sposition to assist or forward the call on to the Coast Guard. Whenthe Coast Guard receives the call, they can immediately access thecaller’s information (such as who they are and the type of vessel) intheir database while they are in transit to the caller’s position.Any time a vessel receives a DSC call, they can store that locationand quickly navigate to that position using a Go To. This makesDSC a time-saver, especially in an emergency situation. In order touse DSC, users must first register their VHF radio with the FCC andreceive a Maritime Mobile Service Identity (MMSI) number.What is a Maritime Mobile Service Identity (MMSI)number?Maritime Mobile Service Identity (MMSI) basically allows a VHFradio to act like a phone. The 9-digit MMSI number acts like aphone number when used in a Position Report and as a uniqueidentifier to the Coast Guard when used in an emergency DistressCall. To obtain a Maritime Mobile Service Identity (MMSI) number,users must register their VHF radio with the FCC (Form 605).Garmin does not supply this number!For more information regarding MMSI numbers, visit http://www.navcen.uscg.gov/marcomms/gmdss/mmsi.htm.GPSMAP 276C Owner’s Manual 113APPENDIX > D IGITAL SELECTIVE CALLING (DSC)
