I'm no Sh3 expert but I think that if they don't exist in your campaign_SCR.mis then they won't be in the game. That doesn't explain why you've seen them before though :huh:

Maybe a stupid question, but are you getting harbour traffic? Not only was Loch Ewe empty of mines in your pic, it was also empty of ships.

Yep, plenty of harbour traffic, when i'm leaving port.

I haven't actually seen any mines but I can only assume that's what they were. When using IuB 1.02 I bumped into them leaving Willemhaven until I realised where to steer clear of.

As for the English channel, likewise I can only assume they were mines that I hit. I had a good 20 meteres of water under me so I couldn't have been hitting the bottom.