The sonar gain is a measure of the amplitude of the output signal. The gain is adjustable. The gain should be increased when working at longer ranges in either mode, and decreased when working at shorter ranges. If the gain is too high, it can wash out the image, especially at close ranges.

The gain can be adjusted by using the Gain slider or the (+) - (-) buttons on the Sonar tab. The current Gain value is displayed above the slider.