The VHF marine band is divided into channels, the frequency and number of which may vary from country to country.
Frequencies and Spacing
Marine VHF channels are between 156.050 and 162.500 MHz and have been selected according to a 25 KHz spacing. The number of channels and their frequencies differ from country to country.
In EEC countries, channels are standardised, but there may still be differences for some countries. For example, in the Netherlands, ATIS channels are used for inland navigation.
There is a new IMO project, designed to change the channel spacing to only 12.5 KHz, thus giving the possibility to increase the number of channels available, thus allocating many of them to the new digital services. It is expected that several more years will pass before this project will become operational, but at that time all current VHF will become obsolete because it is not adaptable to the new system.
Many of the VHF channels are called duplex channels and are those that have a transmission frequency (TX) different from the reception frequency (RX).
These give the possibility to those who are equipped with a professional VHF with duplex functionality to be able to transmit and talk at the same time as in common phones.
For all other common VHF will not be possible to communicate on duplex channels, you must therefore use the simplex channels (those with the same TX frequency to the RX) to allow half-duplex communication.
VHF channel table
The following table illustrates the standard channels in the EEC countries, the data reported have not been taken from official sources and therefore are purely indicative.