Garmin gpsmap 4008 User Manual

Using Sonar

Use the Sonar Setup screen to define and adjust settings universal to all sonar screens.
From the Home screen, select 

 > 

.

Color Scheme—select white or blue. This affects the background on all sonar screens, but does not 

change the Temp Log screen.
Fish Symbols—set how the sonar interprets suspended targets.

The unit does not interpret the sonar return data (default). 

 

Suspended targets appear as symbols. Background sonar information appears, making the 

distinction between fish and structure easier.
Suspended targets appear as symbols with background information shown. The target 

depth of each symbol is also indicated.
Suspended targets appear as symbols. No background information appears. 

 

Suspended targets appear as symbols with no background information shown. The target 

depth of each symbol is indicated.

Scroll Speed—adjust the rate at which the sonar scrolls from right to left (

, 

, 

, or 

). If using a speed-capable transducer, select 

 to have the scroll speed 

automatically adjust to the water speed of your boat.
Surface Noise—show or hide the sonar returns near the surface of the water. Hide surface noise to 

help reduce clutter.
Whiteline—highlights the strongest signal from the bottom to help identify its hardness or softness. 

Off—(default) Whiteline is disabled.
High—the most sensitive setting. Almost all strong returns are highlighted in white.
Medium—many strong returns are highlighted in white.
Low—the least sensitive setting. Only the strongest returns are highlighted in white.

Overlay Numbers—show or hide water temperature, water speed (if your transducer is capable), 

and navigation numbers.

  NOtE: To show water temperature or water speed, change the setting to 

. If the connected 

transducer is capable, the data is shown.