A catfish clonk is a specialist tool used to create a characteristic sound on the water surface. It is commonly used from a boat while the bait is presented vertically below the angler.
Clonks differ in handle design, cup size, angle and material. The best choice is one that can be controlled comfortably and allows a repeatable wrist movement.
The sound depends more on angle and movement than on hitting hard. Practice short, consistent strokes and observe fish response.
Pair with ready-made catfish rigs and boat fishing equipment.