I keep a bottle of Gehrke's Xink Wet Fly Dressing with me. I use it when I want a non-weighted fly to sink just below the surface in very shallow waters or just above some heavy weed beds. Do a word search for Gehrke's Xink Wet Fly Dressing and you will find some places that sell it. The Fly Shop in CA is one of them but many places sell it both in the fly shops and on line.

Larry ---sagefisher---