This will help you when nymph fishing detect takes. But i mainly use these for casting tuition. they are great and easy to see, when connected to the orange pro- Echo solo fly line- So that you can see when practicing if your leader is straightening out- these help you understand and see how your leader lands and straightens when you cast- either on water of grass- a great teaching aid- although they were never designed for teaching- another one of my great teaching aids. These are 8ft long and are floating.