Notes: VDSMS (VHF Digital Small Message Services). Transmissions of short digital messages in accordance with RTCM Standard 12301.1 is allowed.

Four-digit channel numbers

Recommendation ITU-R M.1084-5 Annex 5, adding the prefixes “10” and “20” to the existing channel number instead of the suffixes “A” and “B”, respectively.

Four-digit VHF maritime channel numbers were established by the International Telecommunications Union World Radio Conference meeting in Geneva, Switzerland, 2-27 November 2015.  Its purpose was to improve spectrum efficiency, making allowances for countries making simplex use of duplex channels, just as the US had done beginning in 1965.   US channel 05A is now designated and recognized internationally by the channel 1005, and the US Coast Guard channel 22A is now designated and recognized internationally by the channel “1022”.  These new channel number designations are being displayed on new models of VHF marine radios.

See ITU Radio Regulations Appendix 18, summarized here.

Frequencies are in MHz. Modulation is 16KF3E or 16KG3E.

Boaters should normally use channels listed as Non-Commercial. Channel 16 is used for calling other stations or for distress alerting. Channel 13 should be used to contact a ship when there is danger of collision. All ships of length 20m or greater are required to guard VHF channel 13, in addition to VHF channel 16, when operating within U.S. territorial waters. Users may be fined by the FCC for improper use of these channels. See Radio Watchkeeping regulations for further information.

VHF Maritime Spectrum Chart

NOAA Weather Radio Frequencies

Channel numbers, e.g. (WX1, WX2) etc. have no special significance but are often designated this way in consumer equipment. Other channel numbering schemes are also prevalent.

The order of channels shown is the order they were established and is slowly becoming less "popular" over time than a numerical ordering of channels.

See NATIONAL WEATHER SERVICE MARINE PRODUCTS VIA NOAA WEATHER RADIO and the NOAA Weather Radio Homepage for more information.

Additional Information, Frequencies, & Charts

Also available are International VHF Maritime Radio Channels and Frequencies, Narrowband VHF Maritime Channels and Frequencies, Radio Information for Boaters, and U.S. Coast Guard VHF Distress and Safety Coverage Charts.