>>1149449Actually, we have a few former open mines and diving there is pretty cool. Visibility is nowhere near as good as in a sea but you can see ~10-20m (depends on the day), water is surprisingly ok, and they keep fish in there as a diving attraction. Pic related is a mining machine left there as an attraction.
Sure, it's nowhere near as cool as a coral reef, but it's still pretty fun, and a great opportunity to train diving near your home.
Also turns out Polish divers are pretty well trained in general because they're used to low visibility, and have it really easy once they're in clear waters.
Besides, I think without too much plant life, a lake as deep as 200m should be pretty clean.
