I have seen the most fish caught casting toward the inside of the shoe directly at the other side where the pier ends and retrieving accross the opening into the inner horshoe. So if you are walking out on the pier, stop as you reach the point where you are directly accross from the end of the other side and cast accross the opening. Going all of the way to the end and casting toward the inside works well also. The other good spot is casting into the open lake right where the pier begins to turn, just before the tower/lighthouse thing that everyone relieves themselves on.
Noel