There are approximately 60 VHF channels which all have different uses. the important ones to know are:

– Channel 16: Distress, Urgency, Safety and Calling
– Channels 6, 8, 15, 17, 72, 77: Ship to Ship Communications
– Channel 67: Small Ship Safety Channel (in UK)
– Channel 13: Bridge to Bridge – Safety of Navigation

LEARN: Before the course, make sure you know the main channels and their uses – these are highlighted in colour on the “Channel List” sheet below.

A full channel listing is shown below:

Channel Listing

Learn the commonly used channels and what they are used for (focus your attention on the coloured channels).

Simplex and duplex channels

If you look at the channel list in detail you will see that some channels have a single frequency (simplex) and some two frequencies (duplex).

The single frequency channel are the ones we use most of the time (with a few exceptions).

The duplex channels use a different frequency to transmit and receive. Therefore if one vessel transmits on a duplex channel, no other vessel can hear them. These channels are for communication with a shore station which will have their radio set up to transmit and receive on the opposite frequencies.

Duplex channel are useless for ship to ship communication and are a legacy of ship to shore telephone calls – a service which was run by BT in the UK up until the 1990s.

The only duplex channels routinely used in the UK today are:

– Channel 80: for Marinas, be careful when calling a marina on Channel 80 as you will not expect to hear other boats calling the marina only the marina’s response.
– Channels 23, 26, 86: used by the coastguard for weather and navigation broadcast. The duplex channel here mean that no ship station can block their transition.
– Channel 65: used for communication with NCI lookouts

Channels we use

Once you eliminated the vast majority of duplex channels, you can see that we are left with very few channels to “play with”.

Channel Use
06, 08, 72, 77, 15, 17 Ship to Ship
11, 12, 14, 69, 87, 88 Port Operation
13 Bridge to Bridge – Safety of Navigation
16 Distress, Urgency, Safety & Calling
62, 63 and 64 (updated September 2017) HMCG – Weather & Nav Warnings (Duplex)
65 NCI
67 UK Small Ship Safety Channel
80 UK Marina Channel (Duplex)
M1 (37), M2 Sailing Clubs



International or US channels

Many radios will give you the option of using different “sets” of channels. For example “U” for US channels and “I” for International channels.

In the UK and Europe you must by law have your radio set to the International set of channels. You will need to check in the manual for your radio how to change between the different sets of channels. It is possible to buy radios which only use US channels – these are also illegal to use in Europe.

Channel labels

Some radios (including the ICOMs we use) display the channels use below the channel number on the screen. For example, when you tune to channel 06 it might say below the number “Ship to Ship”.

Even on the best radios, these labels are not always correct.


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