A gneiss spot for fishing?

We had trout that we caught a few days ago for dinner tonight. Fishing tomorrow (at 6.00am) is going to be on this loch. So what (you are thinking) made us chose this one? was it the write up in the fishing guide? The tip off from a well informed local? A quick query on Google? No..... it just looks great! Who wouldn't want to spend a couple of hours fishing here? I'll let you know how we get on.