Garmin gpsmap 198c sounder Manual Do Utilizador

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When the sonar sound waves are reflected back by the bottom, 

a hard bottom returns a stronger signal than a soft bottom. A 

thin whiteline indicates a softer bottom, while a thick whiteline 

indicates a harder bottom. Normally, a red line is used to show the 

point where water meets the bottom. This line follows the bottom 

contour, along with any significant objects lying on the bottom. 

The unit uses the whiteline function to make the bottom layer 

information easier to distinguish.

Thick 

Whiteline: Hard 

bottom

A rough definition of a thermocline is a break in water where 

the water temperature changes faster than the water above it. 

Thermoclines are shown as the weakest colors.
One of the unique features offered by Garmin is See-Thru

®

 

technology, which allows the GPSMAP 198C Sounder to hear 

both weak and strong signals simultaneously so as to identify 

fish returns under the toughest conditions, such as suspended in 

thermoclines or even hiding near structures. See-Thru technology 

allows the transducer to see through thermoclines and locate fish.  

Thermocline