Garmin gpsmap 495 Manuale Utente

Setting up and Using Sonar > 

Using the Sonar Page

Zoom—used to quickly select a zoom scale or to split the screen. 

When a scale other than No Zoom is selected, the Adjustment Menu 

shows a new selection labeled View or Span. The Zoom function is 

divided into six levels: 

2X Split—shows two reduced-size sonar pictures at the same 

time. The right half of the screen shows the complete sonar 

picture at its original scale. The left half shows a portion of the 

original picture at 1/2 depth scale.
2X Zoom—shows the 2X zoomed picture on the full screen.
4X Split—shows two reduced pictures, the right at the original 

depth scale and the left at 1/4 the original depth scale.
4X Zoom—shows the 4X zoomed picture on the full screen.
Btm (Bottom) Split—shows two reduced pictures, the right at 

the original depth scale and the left showing sonar returns from 

the bottom up. All target depths read as a distance from the 

bottom.
Btm (Bottom) Lock—shows returns from the bottom up on the 

full screen.

  NOTE: Quickly zoom in and out of the Sonar Page by pressing 

the In and Out keys. Stop the zoom function by pressing the 

Out key until the No Zoom setting appears. 

View/Span—available when a Zoom scale other than No Zoom is 

selected. The View or Span setting is used to change the viewing range 

of a zoomed screen. If the screen is 2X or 4X split, only the zoomed 

portion on the left side of the screen is affected by the change. If the 

screen is Bottom Split or Bottom Lock, Span adjusts how far off the 

bottom the unit shows data.

Gain—allows you to control the sensitivity of the unit’s receiver, 

which provides flexibility in what is shown. To see more detail, 

increase the receiver sensitivity by selecting a higher gain. If there is 

too much detail or if the screen is cluttered, select a lower gain.
Target Level—adjusts which colors are used to show sonar 

information. A Color Bar appears on the right side of the screen as 

you adjust this setting. A higher percentage results in more strong-

signaled colors shown on the sonar screen. A lower percentage 

results in more weaker-signaled colors shown on the sonar screen. 

This setting does not increase or decrease the unit Gain.
Whiteline—controls how the unit shows information about the 

bottom type (hard or soft). With the Whiteline Off, the bottom return 

shows as red. Set Whiteline at 

Normal or 1–100% to determine 

bottom hardness. See 

Frequency—allows you to choose a transducer frequency. 

Frequency refers to the “pitch” of the sound that the transducer 

sends and receives.