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.
A "Shooting Head' is a short fly line with a specific sink rate. These are 30 feet with loops at each end for quick change loop-to-loop connections. This line will sink at the rate of 6 inches per second, at rest. I rig them by adding 10 or more feet of leader material out to the fly. Behind the head you can use monofilament line. I prefer to use braid because it is much narrower, giving less lift. Braid also does not stretch which aids in more positive hook ups. These heads were purchased as a close out from Cortland. $19.95 while supply lasts.