I am going to set up a trotline along a bridge's pillions. The river has a fairly long stretch here and the depth is consistent. The current is relatively strong. I consistently catch perch and crappie here, but have never catfished. I think I may find a good flathead here. Would you put the trotline so that the hooks are on the up side of the rivers pillions or would you put them on the down river side? Also, I will set one at a felled tree. We have put the trotline on the down river side in the past, and consistently catch them at the edge of the tree, but none from the bank to the tree's end where there is no current. Would there be an advantage of laying the line up current above the tree?