Dsc Tab - Garmin GPSMAP 178 Owner's Manual

DSC Tab— allows to control and set up DSC (Digital Selective Calling) features on the unit.
What is Digital selective calling (DSC)?
Digital Selective Calling (DSC) uses marine VHF radio and Global Positioning System (GPS) tech-
nologies to transmit and receive location information. DSC is used by mariners to assist them in two
major areas: Distress Calls and Position Reporting.
An emergency DSC Distress Call allows a vessel in trouble to transmit a substantial amount of
information in a single transmission 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' s position to assist or forward the call
on to the Coast Guard. When the Coast Guard receives the call, they can immediately access the caller' s
information (such as who they are and the type of vessel) in their database while they are in transit to the
caller' s position.
A non-emergency DSC Position Report allows mariners to exchange and display the positions of one
another. Once a DSC position is received, the mariner may choose to create a waypoint or to show the
received position on an electronic map.
Any time a vessel receives a DSC call, they can store that location and quickly navigate to that
position using a Go To. This makes DSC a time-saver, especially in an emergency situation. In order to
use DSC, users must first register their VHF radio with the FCC and receive a Maritime Mobile Service
Identity (MMSI) number.
What is A Maritime mobile service identity (MMSI)?
Maritime Mobile Service Identity (MMSI) basically allows a VHF radio to act like a phone. In order
to make a "call" on a phone, you first need a phone number to dial. The 9-digit MMSI number acts like a
phone number when used in a Position Report and as a unique identifier to the Coast Guard when used
in an emergency Distress Call. In order 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!
Reference
Main Menu: DSC Tab

DSC Tab