Sonar Sensitivity

Category: Electronics

Sonar sensitivity controls how much of the returning echo signal is displayed on screen. Higher sensitivity shows weaker returns (small fish, baitfish, thermoclines, plankton clouds), while lower sensitivity filters out weak signals and shows only strong returns (bottom, large fish, dense structure). Finding the right sensitivity setting is one of the most important skills in fish finder operation. Too high, and the screen is cluttered with noise that obscures real targets. Too low, and you miss fish and subtle structure. The optimal sensitivity setting changes with depth, water conditions, bottom type, and the specific sonar technology being used. A good starting point is to increase sensitivity until you see surface clutter (noise near the top of the screen), then reduce slightly until the clutter disappears — this ensures you're seeing everything the transducer can detect without overwhelming the display. Most modern fish finders offer Auto sensitivity modes that adjust dynamically, but experienced anglers often prefer manual control for specific situations. In very deep water, sensitivity typically needs to be increased to maintain bottom contact and display fish marks. In shallow water, sensitivity often needs to be reduced to prevent bottom interference from overwhelming the display.