The CDC (Cul De Canard) feather has wonderful floating capabilities, one of its best uses is in the CDC buzzer. A deadly pattern wherever buzzers are hatching. The olive CDC is an ideal fly in the UK for when snails are being taken by trout, this is around late July and August when the annual snail migration takes place. Try this fly when trout are on rising on the water but are not taking normal terrestrial patterns. Used on a floating line, the fly is cast out and then either wait for the trout to take the fly, cover a rise with the fly or pull the CDC under the surface of the water and allow it to resurface with the buoyancy of the CDC feathers, the latter method can have dramatic catching effects.