Garmin gpsmap 495 Manuale Utente

Setting up and Using Sonar > 

Using the Sonar Page

When combined with a GSD 20 or GSD 21 Sounder Module, your 

GPSMAP 495 becomes a powerful fishfinder/flasher with the Sonar 

Page. If a GSD 20 or GSD 21 is attached, but the unit does not 

detect a transducer, a “Sonar Turned Off” message appears across 

the Sonar Page. If a GSD 20 or GSD 21 is not attached, the Sonar 

Page only appears when the unit is in Simulator Mode. 
The middle of the page contains a right-to-left moving sonar image 

of the water beneath your boat. Items appear as they pass under your 

transducer. Those items on the right side of the screen are closer to 

you than those on the left. Along the right side of the screen is an 

adjustable scale that reflects the depth of the area being shown. The 

top-left corner shows the Adjustment Option, the depth, and the 

water temperature. 

The sonar returns show as red (strongest), then orange (strong), 

yellow (medium), green (weaker), and blue (weakest). The Fish 

Symbols option allows you to view the actual sonar data, a fish 

symbol or a combination of both. When the unit is set to 

Dual, the 

appearance of the fish symbols changes. Fish symbols from the 

center of the beam (200 kHz) are solid (or narrow arches), but the 

returns from the edges of the beam (50 kHz) are hollow (or wide 

arches). 
The Sonar Page can also be set to show a split screen view of a 

zoomed portion of the sonar, bottom lock (screen scaled from the 

bottom up), or a combination of these options. For example, you 

can choose to show dual frequency at a 2X zoom (Dual 2X) on one 

half and normal range dual frequency (Dual) on the other half. The 

current display mode is shown at the bottom of each sonar screen.