Q: How do I make wet flies “skitter” on the surface?
—Jim from Warren, PA (via the Ask MidCurrent form)
A: The answer depends on the kind of water you’re fishing, on the equipment you’re using, on the angle of the light, and so on.
Ideally, you should be just close enough that you can make the cast and achieve the required drift. If you’re too close, you risk spooking the fish; if you’re too far away, and you’re not going to catch it anyway because your fly will not even reach the target or will drag once it does. As simple as this seems, figuring out how close to get to a trout is a very complicated proposition because of the number of factors involved.
Read the full answer here