Not the most unusual occurrance, but when you think of the age of some of these things now, and the contents of some of the ships that go up and down there, thank goodness for the Royal Navy!
Believe it or not Jim.. the majority of these WWII German mines are found by fishermen innocently going about their business. Imagine the shock they must have pulling them to the surface! :o I served on a Minehunter some years ago (these differ from a minesweeper in the way the mines are found and disposed of) and we had to get rid of a couple.. both of which were pulled up by trawlers and in different parts of the UK. The last one was off Dover and still in remarkably good nick considering the amount of time it had spent on the sea bed :o We blew it up.. having first extracted the lobster living in the tail (this ended up on the Captains table I might add)