The Scully Zonker, is a great 3D baitfish. The fly can imitate a variety of food but for South African, depending on the time of the year it will represent either a tadpole, dragonfly nymph or minnow.
Tied with a Zonker tail the fly moves very naturally in the water but unlike a lot of traditional patterns, the fly holds a good profile at any angle. The small orange undertag adds a nice touch of colour to an otherwise very natural fly, acting as an attractor.
Fish this pattern on either an intermediate or full sink line. Fished quickly in open water the fly will suggest a baitfish, but fished slowly along weedbeds and the fly suggests a dragonfly nymph.
Tan is a great colour for gravel section of the dam, especially near a drop off.