That said, on the rivers here that have more sedate flows I will always have crayfish flies ready, especially early in the year. Bass like them, and numbers of fish always seem higher. There is something of a numbers vs quality element, but good size fish come to both methods.
I'm always messing around with my crayfish patterns and I carry a few different flies for different rivers, or different presentations. There' a common theme that of the best patterns, none of them really look much like a crayfish to a human eye. And that's important. More and more nowadays you see cray fish patterns with claws, legs, eyes, antennae and shiny, resin covered carapaces. To my mind they're a waste of time. It's possible that I've mentioned this in a previous FP as it's a drum I often bang, but Several years ago I read about Berkley's R&D department testing various hookless soft plastics on bass in their tanks. I can't rememebr the exact numbers but the results showed that both largemouth and smallmouth had a strong preference for fewer appendages. It was siginificant, if a clawed version is the baseline it was something like 1 claw 40% more likely to be eaten and no claws 60% more likely to be eaten. Unfortunately for Berkley, market research found that people don't want to buy plastics without plenty of wiggly flappy bits. Much like most fly tiers don't seem to want to tie a cray fish without squeezing as many different "triggers" as possible. My own experince is in line with the Berkley findings. Years ago when I fist discovered smallmouth in Japan I tied up the usual big crayfish patterns that you'll find online, and although I did catch some fish I was able to watch far more fish backing off the fly in the clear water fisheries I used them in. The same fish would often eat a wooly bugger in roughly the same size.
So over the years I've been tweaking and messing around with various patterns and I've come up with a few points that I think are important in making a good crayfish fly, that presented in the same way will be eaten more often than a more traditional imitation.
1. No claws.
This makes fish more likely to eat and allows the fly to sink faster. It also makes for a quicker tie so you don't feel so bad about losing them in the rocks.
2. Offer a near cylindrical or teardrop profile
Again, better sinking, but also is similar in shape to an unsuspecting crayfish going about its business (cylindrical) or a fleeing crayfish skooting away from a predator (teardrop)
3. Use materials that move especially while the fly is stationary
Movement is good, it makes the fly look alive. There's a trade of from a sink rate point of view, but a couple of silicon legs floating up from the stationary fly move in the lightest current. A lot of fish eat the fly at rest after a couple of hops, especiallyfollowers that have already tapped it without commiting. I'll let a fly sit for over a minute at times.
4. Use as little weight as possible
You need enough weight to find and hold bottom, but just enough is better than too much. I always carry my crayfish in a couple of weights, ideally you want to be able to lift the fly slightly with a short pull but have it back on bottom near immediatly. If I can get away with a small dumbbell that's better as the fly will hop better and hang up less.
5. Hotspots are good.
Rather than adding rattles etc. a little bit of fluorescence can really help the fish pick out your fly on the bottom. Just don't over do it.
In the POD you'll see 2 crayfish patterns, 1 is Whitlock's near'nuff and the other is just a basic pattern that I use. I'm not saying the near'nuff won't work, it will, but it'll work better after a couple of fish have removed the claws. So why bother tying them in? The same goes for the eyes and tail. Either of the other patterns are much quicker to tie, more durable and at least as effective. Yesterday the little ginger guy accounted for 5 fish with one around 50cm (20") which is great for the heavily pressured rivers around Tokyo.
Tomorrow I'm going to explore a new river that I know has some smallmouth in it, looking at the maps I'm pretty sure there will be some good crayfish water to have a search in. I've a few more days fishing before I go back to work to and hopefully the water will stay cold enough that the bass don't start bedding up for the spawn till I'm back in the office, as that's when they should be left alone.