I have, quite literally, dozens of crayfish flies in assorted "ties". The pattern above is one that I find myself using quite often when I'm fishing skinny water for carp. It works quite well, sometimes. I also tie a much simpler pattern in olive, another good carp fly and one that has caught a few rainbows on a creek 80 miles or so east of Ephrata.
I am gathering ideas and a pattern is slowly forming in my mind. However, I have not thought about a floating pattern. I'll have to tie a few of those just for kicks. FYI, I am going to Chile and then to Argentina. The guy from Chile said they have lots of crayfish in the rivers they fish, and the crayfish take on the color of the bottom. After, Chile I go back to Jurassic Lake in Argentina.
There may be regional differences, but generally the word for both crab and crayfish in Spanish is the same: cangrejo. Therefore we qualify it when necessary by adding “de mar” (from the sea, saltwater) or “de río” (from de river, freshwater)