Trout are selective to the depth at which they are searching for food. If trout are chasing shad at the surface and you are trolling 60 feet down you will not catch many fish. The correct depth is more important than boat speed or fly color. Below are some of the line options I use to go down the water column, seeking the proper depth.
Jay Fair Trolling Line $54.50
LC-13 Head Building Kit. $15.95
Kerplunk Lead Core, 100 yds, 18#