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Rescue 21: Digital Selective Calling

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Rescue 21 for Boaters

Rescue 21 will increase the Coast Guard’s ability to respond to distress calls in the coastal zone. However, you can help us improve response time by using a marine-band VHF-radio equipped with digital selective calling (DSC).

Why use a radio equipped with DSC?

With the push of a button, your DSC radio will send an automated digital distress alert containing your Maritime Mobile Service Identity (MMSI) number, position, if interfaced with GPS,  and the nature of distress to other DSC-equipped vessels and rescue facilities. As a result, the Coast Guard is able to respond more quickly and to more accurately identify the location of the distress call. For more information on DSC and how to send alerts and test your equipment, check out the Coast Guard’s Navigation Center website.

Get your MMSI number

To obtain and register your MMSI number, check out the Boat U.S. and Sea Tow MMSI programs. Both have been certified by the Federal Communications Commission and the Coast Guard.

Vessel Safety Check

The Coast Guard Auxiliary is available to help local boaters ensure that their radios are in good working order. Logon to to schedule a vessel safety check in your local area. Examiners also can educate boaters on the importance of properly connecting Global Positioning System equipment to your VHF-radio to ensure a DSC transmission provides proper position information.

Sending a DSC message directly to Coast Guard Sectors

DSC distress alerts will be received by the Coast Guard when Rescue 21 is fully operational in your area. Listed below are the MMSI numbers for Coast Guard sectors and groups that have Rescue 21. These numbers can be used to send a DSC message directly to Coast Guard units.

Rescue 21 VHF DSC MMSI Numbers
Sector/Group MMSI
Baltimore 003669961
Boston 003669901
Buffalo 003669960
Charleston 003669907
Corpus Christi 003669916
Delaware Bay 003669905
Detroit 003669930
Guam 003669994
Hampton Roads 003669922
Honolulu 003669939
Houston/Galveston 003669915
Humboldt Bay 003669909
Jacksonville 003669891
Key West 003669918
Lake Michigan 003669933
Long Island 003669931
Los Angeles/Long Beach 003669912
Miami 003669919
Mobile 003669914
New Orleans 003669908
New York 003669929
North Bend 003669911
North Carolina* 003669906
Northern New England* 003669921
Columbia River 003669937
San Diego 003669913
San Francisco 003669926
San Juan 003669992
Sault Ste Marie 003669935
Puget Sound 003669938
Southeastern New England 003669928
St. Petersburg 003669917
All USCG coast stations in the United States 003669999
International MMSI number designated for all coast stations



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Last Modified 2/26/2016