The approaches’ goal is to place an angler you into the best position to present the fly without alarming the fish. The following variables influence your approach: fish’s position, water clarity, light intensity, hatch intensity, current speed, wind direction, cover placement, casting obstructions, and current maladies and sound vibrations.
In moving water, fish face upstream. Before planning an approach take into account the fishes’ location in terms of its exact position and depth.
Clear water improves the fishes’ vision; stained water obscures its’ vision. In addition, fish are more alert in clear water as compared to stained water.
Light intensity plays a vital role. With increased light the fishes’ vision improves, and the more wary they will become of predation.
During heavy hatches the fish may hold just below the surface; consequently, this restricts their vision window. When hatches are sparse fish can hold deeper so that they can view a wider area looking for insects.
Current speed influences the vertical position that a fish can hold. The faster the current the less likely a fish can hold close to the surface.
Breezes cause the surface to be broken up, and this impairs the fishes’ vision. Calmer water presents the fish with a clearer vision field.
Bank side and aquatic cover can impair the fish’s vision; consequently, use bank side brush to conceal you during your approach, and to hide your position. Although light refraction can sometimes allow fish to see around corners, fish can see you when you cannot see them.
Design your approach so that your final position is not complicated by casting obstructions. Bank side cover may impair your casting stroke making it difficult to make a presentation.
Current eddies and seams can perplex your presentation by causing undue drag. Whirlpools and conflicting currents play havoc on your flies drift.