ENS Jodie Knox, USCGOffice of Search and Rescue (CG-534)

What is DSC?Digital Selective Calling (DSC) Digital transfer of information between

radiosInstantly sends an automatically formatted

distress alert to the Coast Guard and other vessels nearby

Provides a non-experienced boater a one-touch button for distress

Privately hails other DSC equipped vessels or shore stations*

Decreases non-emergency radio traffic on emergency channels*

Prevents missed distress calls with continuous transmission*

Transmits Maritime Mobile Service Identities

Transmits GPS location of caller*

Notifies boater of a call and automatically switches to the channel caller is waiting on*

What does DSC do?

How DSC Works

DSC Alert Signal

DS

C A

lert

Sig

nal

DSC Alert Signal Relayed

Acknowledgment sent

Acknowledgment sent

Maritime Mobile Service Identities (MMSI) DSC radios MUST receive an MMSI to function properlyUniquely encoded nine digit number with

vessel/owner’s information (like a phone number)Stores vessel information, owner, etc…Identifies and helps find boater in a distress situationCoast Guard maintains database for distress

information retrievalStore other vessels MMSI’s into your radio (like a ‘contact

list’)You have to know a boater’s MMSI to call them

What is MMSI?

It is FREEOnly takes a few minutesOnce you obtain your MMSI, enter it into your DSC radio

Some radios only give you two chances; however, a boater can obtain a manufacturer ‘re-set’

Getting a MMSI

BoatUS: http://www.boatus.com/mmsi/instruct.htm

SeaTow: http://seatow.com/boating_safety/mmsi.asp

U.S. Power Squadrons: http://www.usps4mmsi.com

FCC Online Licensing System: (for international voyages) https://wireless2.fcc.gov/UlsEntry/licManager/login.jsp

U.S. Coast Guard Background on MMSI numbers: http://www.navcen.uscg.gov/marcomms/Gmdss/mmsi.htm

Obtaining an MMSI

What can you do to help?

ENS Jodie Knox, USCGOffice of Search and Rescue (CG-534)