And now on a serious note...
With a bit of work you could turn it into an excellent sports facility.
You could have rock climbing, diving (both scuba and high board) canoeing, abseiling, base jumping, bungee etc etc etc.
I actually think with a bit of thought it could be turned into a unique fishery, accessed by boat. Just because its 200 feet deep does not mean that the fish will be 200 feet down. I have fished plenty of deeper lochs that have had large shoals of Charr in the top 50 feet.
Imagine that, a Charr fishery within Aberdeen..how amazing would that be? There are other species that would do ok, like the Perch, but I was thinking more along the lines of rare fish that very few people have the chance of fishing for