Body Natural grey dryer lint (CDC barbs spun in a dubbing loop)
Wing Natural grey or Khaki Campbell (2 CDC feathers)
Tail White, blue or dark green material (2 fibres of Krystal Flash)
How to tie it
Start red UTC 70 at the 75% mark and wind back to the bend, leaving a thin band of red showing at the rear where it acts as a subtle hot spot under the CDC body.
Tie in two fibres of Krystal Flash as a short tail, about half a shank long. Two fibres is deliberate: enough to suggest a trailing shuck without adding weight or drag.
Build a dubbing loop, load it with natural grey CDC barbs stripped from the stem, spin it tight and wind forward to the 65% mark. A CDC body traps air along the whole fly, not just in the wing, which is what keeps it riding high in broken water.
Stack two CDC feathers and tie them in as a down wing running just past the bend, then split the tips into a shallow fork with a couple of figure-eight turns. The fork gives the fly its name and stops the wing collapsing into a single wet clump after a few casts.
Sweep any stray body barbs back over the wing base and take two or three tight turns in front to lock everything and hold the wing low over the body.
Whip finish with a small red head and trim the wing square at the tail. On fast water where a hackled caddis gets dragged under, the all-CDC build re-floats with a couple of false casts and no floatant.