Sighters are game changers. A visible sighter allows you to stop guessing where your fly might be and know where it is instead. By having a visual reference at a fixed point on your leader, you can track the movements of that leader, in relation to the currents, and have a very good idea of what your flies are doing under the water — or on the surface.
Not only do I build a sighter into my nymph and streamer leaders, I also add small, subtle sighters into my dry fly leaders. As my friend, Jimmi Ray, says, “Why wouldn’t you?” Sighters, however, are a staple in tight line and euro nymphing leaders, and in the Mono Rig.
I absolutely believe in the effectiveness of long mono leaders for nearly every underwater presentation to river trout, but here's one major drawback: without the fly line, there’s nothing to look at. A sighter gives that visual back, better than ever.