I recall in the 70's a TU16 (Badger) flew inside the 'mouth' of the Firth of Forth just outside the 12nm line, and I believe it was at low level.
Also in the 70s I recall a couple of Badgers over the North Sea taking a look at an exercise we were on - but that was well out of the 12 mile limit. What was mildly disturbing was Northern Radar reporting them as "...
friendly traffic on a reciprocal heading, will pass 2000' below you on your starboard side." Squinting out of my window was surpised to see said Badgers flash past, just as predicted. Still, I suppose they were friendly!