Well, the flat wing folds over the top when it is wet. The fibers of schlappen give movement, as well as the polar flash. There is no way a fish will miss seeing it in the water. I have not used it on a river, so I can't tell you about that yet. It is a light fly, but if you want to add weight to it, you certainly can. The amount of fluoro fibre is very small. It is mainly to give a touch of blue, and shine. I was very generous with the polar flash though. Polar Flash has great movement, and flash. I like the pearl for this pattern. I also like the lighter color lower, then put the blue fluoro fibre on top, before the teal wing is placed on top.