I know Bob recommends weighting his crayfish pattern. But my favorite stretch of water is a very fast moving run (rapids actually). So I figured even with weight, the fly would still just get pushed quickly downstream and never even have a chance to hit bottom. I was confident that Bob's crayfish would look like a real crayfish getting tumbled uncontrollably downstream, by the very swift current, whether or not it was weighted. (And Bob did build a little bit of weight into the fly with lead wire used on each side of the hook shank.)
So I tied on a Clouser Crayfish and had at it. I cast it across stream or slightly downstream into the rapids. (I don't like to cast upstream in rapids because it requires endless mending.) I proceeded to catch 7 smallies in about an hour, played a few more, plus multiple other strikes - all on the same fly. By the time i was done the fly was quite chewed up but still catching fish.
This experience reminded me of what Lefty Kreh (RIP) said on the DVD he and Bob made called "Fly Fishing for Bass', "I have tried scores of crawfish patterns... but the best one I have ever used is the Clouser Crayfish." He wasn't kidding.
If you drift a Clouser Furry Foam Crayfish along the river bottom, smallmouth will crush it! (especially if there are visible crayfish scurrying along the bottom in response to your wading). It still catches even after it’s been deformed by dozens & dozens of fish! Must be how the weight of it is distributed & the movement of how it presents itself along the bottom.
My second cast with the Clouser Feather crayfish resulted in a bass. Many more to follow. Highly effective choice. I’m very happy with its success rate and give it two thumbs up.
My favourite wet fly. I was using the usual suspects such as Pheasant Tail, for a put and take trout farm & lakes, Damerham in Hampshire UK the other day and nothing for a couple of hours, then put on one of these against local advice and bang! A hard fighting rainbow on the second cast. At Damerham, they fight like Sea Trout. Why not a gold or silver headed version?
Clouser's Crayfish was one of my most effective flies for river brown trout in England, such as the Cotswolds and Oxfordshire, also decent for Rainbows in stocked lakes and in Scotland's Rivers. Just a bit expensive to keep losing. I tried similar Cray patterns from others, but less catches.