I had just read a nice article in a flyfishing magazine and it had to do with strike indicators.you here a lot of guys talking about indicators to use , but if you read this article you might think differently.Basically what it said was by using an indicator,it acted as a buoy allowing you to fish predetermined depths.By fishing without one gives you more contact with the fly and you can feel strikes better.And one of the most important things is that nymphs do swim and you cannot get this movement with and indicator.