The Maritime and Coastguard Agency have given early notification to Boat owners, shipping companies and anyone who puts out to sea about a change in some of the VHF channel numbers used to contact UK Coastguard.
As a result of the changes VHF channels 23, 84 and 86 will no longer be used for either Maritime Safety Information (MSI) or Radio Medical Advice.
The channels to use from September 2017 will be VHF 62, 63 and 64. The use of VHF Channel 10 for MSI and pollution control (back up) is unchanged.
Further information here