To keep this simple and avoid loss of comms all we have to understand is that the
(channel) we set on a 8.33 radio is not the frequency that the radio transmits on.
When ATC say " call CHANNEL xxx.xxx set the numbers normal manner.
The radio will not transmit the numbers you have displayed, that is why it is called a CHANNEL
Marine vhf has always used CHANNELS. I think the basic calling CHANNEL is 16, have not a clue
what the actual frequency is.
I posted a link which shows the set/displayed value and the frequency that the radio actually
transmits on.