From a sonar view, select > Sonar Setup > Noise Reject.

Interference

Adjusts the sensitivity to reduce the effects of interference from nearby sources of noise.

When you adjust the interference setting from off through low , medium , and high , noise is gradually removed, but there is little effect on the strong target returns. You should use the lowest interference setting that achieves the desired improvement to remove interference from the screen. Correcting installation issues that cause noise is the best way to eliminate interference.

Surface Noise

Hides sonar returns near the surface of the water. Hiding surface noise helps reduce screen clutter.

Surface noise is caused by interference between the transducer and water. You can hide surface noise to help reduce clutter. Wider beam widths (lower frequencies) can show more targets, but can generate more surface noise.

TVG

Reduces surface noise.

This control is best used for situations when you want to control and suppress clutter or noise near the water surface. It also allows for the display of targets near the surface that are otherwise hidden or masked by surface noise.