Hursty If there is a genuine no deal, each country’s territorial waters extend 12 nautical miles (22 km) beyond the coast, and an exclusive economic zone which I think can extend to about 200 miles if there’s no other land in the way. That is totally Britain’s by the UN Convention on the Law of the Sea, as far as I know, and Britain can then escort out any cunt they don’t want fishing in there.
The EU want Britain to trade away fishing rights in that EEZ for things like access to the EU single market.
In the case of something like the Channel, it’s split down the middle with the neighbour (France in this case).