I'm continually surprised at the apparently tiny number of people who even consider fishing stillwaters with dry flies. During Callibaetis mayfly hatches, fishing a floating emerger or dun imitation can be far more effective than any subsurface technique. Teneral and adult damselfly imitations can be highly effective throughout the day once they have begun hatching in good numbers and will bring up the largest of fish. I've also been able to take fish all day long on emerger or adult midge patterns. Try it, you might like it, and it's a helluva lot more fun than sitting staring at a bobber.