I use the
West Passage seen from the main entrance to Scapa. The West Passage has only a surface 'domino' mine ramp (I can't imagine another name for it; make too many vibrations and the mines will fall down from a ramp, so go at slow speed, at least that's the idea, I was unable to make the mines fall down!), BUT: no mines underwater, and be careful because the depth can go below 15m, you must head back immediately without turning in case of patrol boats, give the 'Alle Kraft zurück!" command.
Of course the main Scapa entrance has mines just floating enough underwater to destroy your hull if you pass over them. And TWoS has added land turrets to spot you. Without these turrets my idea was to follow a merchand going in during dark night to see it crash in the mines or we both go to the other side. This would have owed me a Prien Certificate
Good luck in Scapa !
XS