Has anyone run into the new four-digit channel numbers on VHF marine
radios? In 2012 the ITU World Radio
Conference mandated that simplex use of duplex channels, i.e. the "A" channels used in the US, be designed by a "10" prefix. For example, the USCG channel 22A would now be designated by channel 1022.
The good news is that the long-held but peculiar use of certain VHF
channels in the US is now recognized world-wide. The bad news is having to get used to them. Although the FCC has not yet mandated radios conform to these new channeling scheme, the European standards organization ETSI has, so users of new radios marketed internationally should soon start seeing these new channel numbering. These new radios should still have a US/International switch.
No new channels come from this scheme in the US, just new numbering of certain existing channels. There is one new channel now available outside of the US: Channel 2020.
See the Coast Guard Navigation
Center's US VHF Channels webpage for more details: http://www.navcen.uscg.gov/?pageName=mtVhf
USCG (partially retired)