Digital Selective Calling (DSC) is primarily used to initiate distress calls to shore stations and other vessels via your DSC radio and provides recipients of your emergency call with:
-Your Vessel’s Identity
-Your Precise Position (if interfaced with GPS)
-Your Unique MMSI Number (Maritime Mobile Service Identity)
-The Nature of your Distress
All DSC-equipped shore stations and vessels will hear your distress signal as an alarm. It will be repeated every 4 minutes until acknowledged. A DSC alert signal has a 15% greater range than a voice transmission and therefore is more likely to reach a vessel or rescue centre.
In a potentially dangerous situation, a DSC alert signal is the quickest way to initiate emergency communications with ships and rescue coordination centres. DSC saves vital time by allowing you to speak to the emergency authorities and plan your next move. Although ch16 is also a channel for emergency rescue, it is still not as fast as DSC. It's difficult to describe the location of ch16 when you are in danger. DSC will not, it will directly send your current location to the surrounding ships and coastal rescue center, can accurately get your location, greatly reducing the difficulty of rescue
If integrated with GPS navigational equipment (highly recommended), a vessel's position and time of transmission are automatically included in the DSC distress and urgency alerts, an important point when you find yourself in trouble. If your DSC is not linked to a GPS, manual input of your coordinates is required. When linked to a GPS, it is simply a case of pressing the red DSC button to summon help.
All large vessels and almost all Coastguards over Europe are fully-equipped for DSC and will respond instantly. GMDSS is an automatic, worldwide system and can be used anywhere, avoiding possible language barriers. If you are in trouble, DSC allows you to call every other radio in range, simultaneously.