The "problem" imho is that mines is something you place to protect something very specific and sea provinces are really big. One of the channel provinces is 160x180km or about 35 square km you would either have to handle placement of mines within a province and track ships compared to that (which i dont think is viable because its not within the scale of the game) or you would have to apply a attrition modifier to fleets in the province. However an attrition modifier kinda neglects the function of mines which imho is to provide manmade reefs so the enemy doesnt know where they can sail if they wanted to attack a certain high priority target and to provide critical hits on ships if hit.
Tbh i think they are outside the scope of the game and i cant think of a way to implement mines without them either adding lots of micro or just being an indifferent feature that doesnt add anything to the game.
There are, however, few places of interest with regard to such provinces. As an extreme, you can't just mine the North Atlantic but you could certainly mine the passages through the sea south of Kristiansand or the waters between Odense & Malmo. Germany developed the quite nasty habit of dropping a few mines in the Thames Estuary which was (usually) very effective at isolating London from the sea for weeks at a time. The mouth of the Mersey was another favourite resulting in severe losses of shipping bound for Liverpool.
Typically, mines were used to blockade ports, straits or channels. The English Channel being one of the first to be blockaded with mines by Britain. You don't need to entirely fill such a sea-zone with mines. All you need is a few strings.
The mines laid by Britain in the English Channel mentioned in the article are of particular interest as it describes them as "anti-submarine" mines. How does a mine know if it's contacted a submarine rather than a ship?
The English Channel was, most definitely, open to navigation by surface ships (even German ships) but definitely closed to submarines. So... did every man & his dog have a map showing where not to go? I'm pretty sure such a map wasn't captured by Germany. All they'd need to do is watch for a few days to see where ships went. Or was it simply that these mines were tethered in such a way that they remained submerged and, therefore, were only a threat to submerged units? This implies that a
surfaced submarine would be able to pass over them without incident. Other than running the gauntlet of the RN, RAF and whatever coastal batteries were awake of course.
I think it's a fascinating subject and, considering that for part of the war at least, losses to mines was second only to submarines and remained significant throughout the war.
I'd love to be able to "bottle-up" the German fleet, or Scapa Flow so that Bismarck can escape in to the Atlantic.
My only reservations are:-
You can only mine certain sea zones. Typically those with ports and (you're mining the ports so movement isn't restricted other than to/from the port) channels & straits.
The AI might not be able to use the weapon "sensibly" and it would put yet another tool in the hands of the player. To mitigate this, you could have a switch to turn mines off, just as we have on that turns nukes off.
