CONTINUOUSWAVE

The U.S. Coast Guard has sent out a notice advising all USCG stations to add the four-digit VHF Marine Band channel identification numbers in addition to the legacy channel numbers in their marine information broadcasts. An excerpt from the notice appears below:

1. This ALCOAST announces a significant change to marine information broadcasts. Effective immediately, when making the preliminary broadcast for urgent marine information broadcasts (UMIB), mariners should be directed to switch to channel 1022 (pronounced Ten Twenty-two) and channel 22A to prevent missing critical broadcast information. This change is critical as radio manufacturers recently began distributing updated equipment that does not recognize the legacy channel names.
2. Radio manufacturers have begun using the International Telecommunications Union (ITU) channel identification standard which includes the use of four-digit channel names in place of the "A" or "B" suffixes."
3. A full list of 4 digits channel names is on the NAVCEN website [at] https://www.navcen.uscg.gov/us-vhf-channel-information
   
   Coast Guard working channels are as follows:
   

   CHANNEL  ITU CH  FREQUENCY
   21A      1021    157.050 MHz
   22A      1022    157.100 MHz
   23A      1023    157.150 MHz
   81A      1081    157.075 MHz
   83A      1083    157.175 MHz

4. All two-digit channel assignments, designated uses, and frequencies remain the same.

The impetus for this change in use of channel names spoken during USCG information broadcasts is apparently due to the influx of newer VHF Marine Band radios in use that no longer provide the legacy "A" and "B" channel suffix designations, such as "Channel 22A" in the radio's channel selector display.

The use of four-digit designations for VHF Marine Band channels goes back about nine years ago, to November 2015, but has been slow in being adopted by VHF Marine Band radio manufacturers.