What is Rescue 21? Rescue 21 is the Coast Guard’s advanced direction-finding communications system. It is replacing the National Distress Response System which has been in service since the 1970’s. It provides an expanded frequency capacity which improves interoperability with other Department of Homeland Security agencies as well as other federal, state, and local agencies. This includes the capacity for using P25 digital technology and encryption capability in addition to the current Marine VHF frequencies.. The system will also allow the simultaneous monitoring of multiple VHF channels, enhanced clarity, and support of Digital Selective Calling (a system for transmitting GPS enabled distress messages). It will also close gaps in coastal coverage areas. Rescue 21 also incorporates an integrated direction finding system. Another interesting feature of the Rescue 21 System is that it provides portable, deployable towers and equipment for the restoration of communications in the aftermath of disasters such as Hurricanes Katrina, Gustav, and Ike. This will quickly allow the Coast Guard to re-establish their communications both within the agency, with other agencies, and with the public during an emergency or post-disaster.
A map of Rescue 21 coverage: Green areas indicate locations in which Rescue 21 is operational; the dots indicate tower locations and the circles indicate tower coverage. The blue areas indicate future Rescue 21 locations. (Diagram from the General Dynamics C4 Systems website)
A diagram of how the Rescue 21 system works utilizing multiple tower sites, and portable towers and equipment. Note the Disaster Recovery System (the deployable towers and equipment mentioned above) on the left hand side of the diagram.
What does this mean for the radio hobbyist? At this point, based on my monitoring experience, it means three things (Note that following applies to communications involving USCG Station Tybee and the MH-65s from USCG Air Station Savannah):
1. You will hear less on the Marine VHF frequencies. Station Tybee has been communicating with its surface assets on federal VHF frequencies that are used by the Rescue 21 system. Some communications with USCG surface assets are still on Marine VHF Ch. 21 (157.050 MHz) and currently all communications with USCG Auxiliary assets and aviation assets remain on Marine VHF frequencies. A list of these frequencies will follow at the end of this article.
2. You will hear an increased amount of P25 digital voice communications with the Rescue 21 system. You will also hear an increased amount of encrypted traffic. Almost all of the transmission I’ve heard from Station Tybee on their new operating channel have been digital encrypted. On the other hand, almost all of the transmissions from the surface assets have been digital in the clear.
3. Because the Rescue 21 system uses both frequencies in the Federal VHF range and digital voice technology, you may have to get some new radio equipment if you want to listen to the Coast Guard. Not all scanners will receive the Federal VHF frequency range (16# - 17# MHz) and many will not receive the P25 digital voice mode. Almost all VHF/UHF Amateur Radio equipment is not P25 digital capable (I believe that Alinco makes some that are capable and it should be noted that the Icom D-Star protocol and P25 are not compatible). Radios like the Radio Shack Pro-96, Pro-106, Pro-197, Uniden BC396 and BC996, and GRE PR-500 and PR-600 are radios that can monitor the unencrypted digital transmissions.
In addition to the common Marine VHF frequencies that are used by the US Coast Guard, you will need to monitor some new frequencies for the Rescue 21 system. Station Tybee has been utilizing Net 113 as the operating channel in recent weeks. The channels are designated with NET 1# and 1## numbers. The frequencies are identical for each 1#/1## combination; the two digit designator indicates analog voice use and the three digit number created by the addition of a one at the beginning indicates digital voice use.
Rescue 21 “NET” Channels
NET 01/101 - 139.9750
NET 02/102 - 140.4750
NET 03/103 - 140.7250
NET 04/104 - 141.6125
NET 05/105 - 150.7250
NET 06/106 - 141.5500
NET 07/107 - 150.3000
NET 08/108 - 162.0500
NET 09/109 - 162.1250
NET 10/110 - 162.2500
NET 11/111 - 162.3250
NET 12/112 - 163.0500
NET 13/113 - 163.1375
NET 14/114 - 164.3000
NET 15/115 - 164.3125
NET 16/116 - 164.5500
NET 17/117 - 164.5625
NET 18/118 - 164.9000
NET 19/119 - 164.9125
NET 20/120 - 165.2625
NET 21/121 - 165.3125
NET 22/122 - 165.3250
NET 23/123 - 165.3375
NET 24/124 - 166.1875
NET 25/125 - 167.9000
NET 26/126 - 168.8625
NET 27/127 - 171.2375
NET 28/128 - 172.3125
VHF Law Enforcement (LE)
LE-A - 167.0875 (simplex)
Sources:
General Dynamics C4 Systems Website
http://www.gdc4s.com/content/detail.cfm?item=816a4a1c-1316-4879-adff-430e9f7972fa
The Monitoring Times “MT Fed Files” Blog by Chris Parris
http://mt-fedfiles.blogspot.com/2009_05_31_archive.html
USCG Rescue 21 Website and Rescue 21 Fact Sheet
http://www.uscg.mil/hq/cg9/rescue21/
http://www.uscg.mil/hq/cg9/programs/pdf/r21factsheet.pdf
US Department of Homeland Security National Interoperability Field Operations Guide (NIFOG)
http://www.dhhs.state.nc.us/dhsr/EMS/pdf/NIFOG.pdf
