So far, that makes two votes for the middle of the pond. The one side of my pond is up high, and I can see into the middle really good, yet never see anything schooling out there. I can cast "almost" to the center, yet nothing. Sometimes I think when I try the boat to get out into the very center, they get spooked, but just not sure.
Pat--- you mention 15' deep, but I assume you are not fishing that deep?
Shorty --- are you trying to match the bug hatch, fly fishing? or ???
