Normally, when you can see carp, you can't catch them. They are likely just sun bathing if they are near surface.
If you are stuck with that venue, the best advice is to throw in a can of sweet corn (or feed corn if you have it for the cost factor) the day before you fish it.
Your setup is fine. I'd use at least a 2oz lead and shorten the leader a little bit (I don't normally go over 6" of leader). Do some research on a hair rig, it does improve the hook up rate and not hard to make at all.
As to where the big carp are, that's the million dollar question. This time of the year carp fishing is harder due to the warm water temperature, they are either spawning or go to deeper water after spawn for cooler/more oxygenated water. You should have more luck fishing the early morning or in the evening for the same reason.
Good luck. I started carping thinking the same way you do, but after a while, I stop going north at all ;-)