Garmin 521 User Manual

Using Sonar

Use the Sonar Setup screen to define and adjust settings universal to 

all sonar screens.
From the Home screen, select 

 > 

.

Scroll Speed—adjust the rate at which the sonar scrolls from 

right to left (Ultrascroll

™

, fast, Medium, or Slow). 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.
depth Line—quickly reference a specific depth (Show or Hide). To 

set the depth of the reference line, select 

, and then press up or 

down on the 

.

a-Scope—display a vertical flasher along the right side of the 

screen.
data bars—show or hide depth, water temperature, water speed (if 

your transducer is capable), battery voltage, cruising, navigation, 

).

NOTE: To display water temperature or water speed, the connected 

transducer must be capable of measuring water temperature, water 

speed, or both. Select 

 to display the values.

appearance—customize the display of fish symbols, whiteline, and 

the sonar color scheme.

fish Symbols—set how the sonar interprets suspended targets.

Select 

 to show suspended targets as symbols with 

background sonar information. 
Select 

 to show suspended targets as symbols with 

background sonar information and target depth information.
Select 

 to show suspended targets as symbols.

Select 

 to show suspended targets as symbols with 

target depth information.

whiteline—highlights the strongest signal from the bottom to 

help identify the hardness or softness. 

Off (default)—turns off whiteline.
High—the most-sensitive setting. Almost all strong returns 

are highlighted in white.

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