Re: here is an interesting fact.,,,,, @John Jennings.
You are correct in both your postings above!
I only mentioned channel 16 as that is the international hailing/distress frequency, although the Merkins, of course have their own, slightly different frequencies than the rest of the planet...
12 miles is the limit of territorial waters, and NoTaMs are also broadcast here (Dover Straits) bi-hourly.
I used to have access to channel 0, which is set aside for Coastguard/Lifeboat use, but unfortunately am no longer involved, and can only listen in... :o(
When inside territorial waters, it is common sense, and courtesy, to have your VHF turned ON, but squelched. Modern short range GMDSS/DSC sets use just milliamps when idle.