104 GPSMAP® 6000/7000 Series Owner’s ManualSonarNoise and Interference SettingsThe noise rejection settings allow you to reduce the interference and the amount of clutter shown on thesonar screen. With the GSD 24 and GSD 26, you can adjust the noise rejection settings for each frequencyindependently.Showing Surface NoiseYou can set whether the returns near the surface of the water appear on the sonar screen. Hide surface noise tohelp reduce clutter.1. From the Home screen, select Sonar.2. Select a sonar view.3. Select Menu.4. Select an option:• For the GSD 22, select Sonar Setup.• For the GSD 24/26, select More > Noise Reject.5. Select Surface Noise > Show.Adjusting the Noise RejectionNote: This feature is available only on the GSD 22.If you have manually increased or decreased the gain setting (page 101), you can minimize the appearance ofweak sonar returns by increasing the noise rejection.1. From the Home screen, select Sonar.2. Select a sonar view.3. Select Menu > Noise Reject.4. Select Up or Down.Minimizing InterferenceNote: These features are available only on the GSD 24 and GSD 26.1. From the Home screen, select Sonar.2. Select a sonar view.3. Select Menu > More > Noise Reject.4. Select one or more options:• Select Interference to reduce the effects of crosstalk and electrical interference.• Select Color Limit to hide part of the color palette to help eliminate fields of weak clutter.• Select Smoothing to make the sonar screen appear more consistent in deeper water.Sonar Screen AppearanceShowing and Configuring a Depth LineYou can set whether a quick-reference depth line appears on the sonar screen.1. From the Home screen, select Sonar.2. Select a sonar view.3. Select Menu.4. Select an option:• For the GSD 22, select Sonar Setup.• For the GSD 24/26, select More > Appearance.5. Select Depth Line > Show.6. Set the depth of the reference line:• For the GPSMAP 6000 series, use the Rocker.• For the GPSMAP 7000 series, touch and drag the line.