The Murray's Crayfish is helping us catch many large bass because it swims like a real crayfish. Fish these with a slow two inch darting action along the stream bottom where the cobblestones range from softball to basketball sizes. The goal is to get these to the bottom without making them sit on the bottom like an anchor. Don't use too much weight, you're best success will come when you find the right balance to get the fly to the bottom while still allowing it to drift. Swing nymphing these flies through the ledges and cobblestones can produce hard strikes and exciting fishing.