Hi Jp.

Vince Marinaro designed the thorax dun for educated trout on flat water, a sparse, clipped hackle reinforces a natural footrpint presentation. By increasng hackle density, clipped hackle flies can be fished on the choppiest of riffles with confidence. I fished the #22 caddis above for several hours early last week, covering flat, broken and very choppy water without issue. A touch of your preferred floatant should work wonders (not least as Marinaro tended NOT to use floatants, and I assume the quality of our genetic hackles today improves on the material qualities he used). I've found a very light dressing of old mucilin to work very well.

Another approach to assist floatation is to treat the fly during the tie with Fly-rite Dilly Wax - add to the thorax before dubbing and/or winding hackle to place floatant right in to the heart of the fly.

Just one small point RE: AK's spent caddis - if the fly takes on water and sits lower... then sub-surface, don't automatically re-treat with floatant but try a few drifts looking for takes on the drowned caddis. Same tactic works very well with spent spinners. You WILL find fish that haven't risen to take up top :ugeek:

Hope this helps.

Best,
Andy