Just a short comment. I got my 12nm as opposed to 3 from Articles 1 & 2 of the Chicago Convention (defining sovereignty of territory) and definition of "Territorial Waters". The attached link discusses territorial waters.
http://reference.allrefer.com/encycl.../waters-t.html
It is my understanding that the UK regulates under the 12nm rule and not the 3nm. If I am wrong, then I apologise.