The fact that the Kevlar lines can not be made to float is not necessarily a bad thing in my view. Sure it would have been nice to have a Tenkara weight fly line that would float for fishing dry flies on lakes, where you do not want a sinking line to pull a floating fly under the water for you. But under windy conditions where the wind creates surface currents in the lake waters, causing a belly in your line that drags the fly through the water unnaturally and creates slack in the line that makes it hard to hook the fish when you get a strike, a slow sinking line will still allow you to fish a fly close to the surface if not on it for a long time, and it will allow you to get drag free drifts and feel strikes because the line will sink below the surface currents on a lake the wind creates.
For stream fishing the fact these lines sink should not matter much if any at all, since you will be holding as much of your line up off of the water as you possibly can nearly all of the time in making stream fishing presentations. Perhaps, at some time in the future Daniel will come a cross a floating line material that can be made into a floating tapered Tenkara fly line for we lake and pond Tenkara fly fishermen to use with dry flies and poppers. The level and tapered sinking Tenkara lines work just fine the way they are with sinking and wet flies in my view.
As for the post above, I really do not know how to respond to it. I don't see that it has anything at all to do with what I was talking about. There is no single fly pattern that is all effective in all situations, and no single fishing tackle method that produces the best everywhere all the time. If some choose to believe otherwise, that's OK with me. After all its your fishing and you should do it as you like.
To the best of my knowledge I have broken no laws and I have no desire to do so. And some people could accuse the one fly Kebari fishermen of being too simple minded and/or too lazy to learn about the aquatic insects and the other food sources that trout eat in the waters where they live. I would not do that, but a plausible case for same could be made by the same logic, or lack there of, that was applied above.
The point I was trying to make in sighting the studies that I sighted is that a lot of supposedly scientific studies are so exaggerated and lopsided in their methodology and conclusions that they have little if any practical applications in the real world where we fishermen live and fish.
The lake I sighted was used because it is the one I am most familiar with and where I have done the bulk of my pattern testing over the years. I am not the only person who fishes there. The trout are not stupid and terribly easy to catch, but they are usually co-operative if you use stealth in your approach, cast accurately and fish patterns representing what they are feeding on when you see them working. I usually fish it early and late in the year, but I have fished it through out the whole of the summer season at times. Since it is located at 9,100 feet above sea level, it is not a place that you can fly fish in the winter and early spring months. This lake has seen the most use of the line treatments I mentioned above with no observable decrease in the trout population.
To say that Rain-X is poisonous to the environment is something of an exaggeration in my view. Here is the label warnings. "CAUTION: Do not expose to flame or store at temperatures above 120*F. If splashed into eyes, flush with water for 15 minuets and see physician. Contains ethyl alcohol (67-17-5), ethyl sulphate (540-82-9), isopropyl alcohol (67-63-0) and siloxanes (63148-62-9, 70131-67-8, 68440-59-5). N.Y.F.D. C of A No.4369 - Container approved VYC Bd of S&A No. 672-73-A. Keep From Children"
While no one should drink this product and denatured alcohol is mildly toxic in its various forms, all of the alcohol rapidly evaporates out of the this product after application in a matter of minuets or less. Rain-X is recommended for use on such household items as house windows, glass shower doors, glass tables, patio doors, TV screens and more. According to the manufacturer Rain-X makes all glass surfaces water and soil repellent. While it is listed as an eye irritant, Rain-x is hardly capable of ending all life as we know it on this planet by applying it to a fishing line.