I have no solution to your problem except to let you know that we have the underwater vegetation here and what I do is locate the "holes or open spots" in the vegetation and put my fly just above the hole and let it drift through the hole and then pick it up and recast. I get many strikes as the fly is drifting through the open space in the vegetation. I also have had very good luck with fishing the edges of the vegetation. Just some thoughts.....
Warren
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.