If you find the fish actually taking the adults mayflies off the surface, then a still-fished dry fly generally works the best. I differ from the person who instructed you to cast to the center of the rise form. Fish in still water are almost always on the move when searching for food, and if you present your fly to where the rise form appeared, in all probability the fish as moved several feet or yards away.

The trick is to try to determine which direction the fish is moving, then present your fly several feet ahead of it where the next rise is expected to occur.

For example, watch for a series of sequential rise forms moving in the same direction. If you see a rise in one spot, then another one a few feet away from the first, and then another, it is probably the same fish moving through the water taking insects as it goes. If you can pinpoint two or three (or more) in a row, place your fly where you expect the next rise to occur.

If, however, the fish appear to be rising to surface food, but they don't actually break through the surface film, they are probably taking the sub-surface nymphs as they ascend to the surface. Most takes will generally be just below the surface, and they will be indicated by a "swell" or "bulge" in the water that looks similar to the rise to a dry fly. Watch carefully, and if you don't see that a bubble or an actual surface disruption, assume the fish are feeding on the nymphs.

If they are, I like to use an appropriate sized nymph on a floating line with a long leader and tippet. The fish is tracked as mentioned above, with the cast being made to where the next anticipated rise will occur. Allow the fly to sink just below the surface (generally without any added weight), then begin a very slow, strip retrieve, moving the fly only 2"-3" at a time. Watch the water behind where you line and leader sink into the water, and if you see a rise form about where you think your fly is moving, tighten-up immediately. Sometimes the fish will hit the fly solidly, leaving no question as to whether a strike has occurred. But just as often as not, the only indication will be a bulge or swirl behind where you leader disappears below the surface.

To be successful in taking fish in still water often depends on good observation by the angler. Concentrate on that and you will increase you likelihood of success.

Good luck and good fishing,

Emerger