Fish rising in the bubble line and nothing floating on the surface? Floating Nymph shucks could be the answer as often seen on Southland Rivers, New Zealand. The name of this fly has been misconstrued. One group thinking it the initials of the originator the American fly tier Andre Puyans, however, he named it A P as in "all purpose".
Apart from being used as a shuck this fly can also be used as a free drifting nymph. We have sucessfully used it as a trailing dropper off a suitable dry fly during a hatch.