Couldn't say Rock, don't really know anything about catching them on a fly rod other than you have to sneak up on them. Really from what I hear, you need to fish more like a crane than a man. Kind of creep out there really slow and post up near where you think they will be cruising by and make the gentlest of presentations of whatever they are in that area to feed on. Have heard that crayfish imitations are a solid bet though, so maybe something of that hue would be good. Anyone care to share?