4
GPSMAP 4000 Series Owner’s Manual
U
Sin
G
S
onar
Setting Up Sonar
Use the Sonar Setup screen to define and adjust settings universal to all sonar screens.
From the Home screen, select
Sonar
>
Sonar Setup
.
Color Scheme
—choose white (black, if using night mode colors) or blue. This affects the
background on all sonar screens, but does not change the Temp Log screen.
Fish Symbols
—sets 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
—adjusts the rate at which the sonar scrolls from right to left (
Ultrascroll
,
Fast
,
Medium
, or
Slow
). If you are using a speed-capable transducer, select
Auto
to have the scroll speed
automatically adjust to the water speed of your boat.
Surface Noise
—shows or hides 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
—shows or hides water temperature, water speed (if your transducer is capable),
and navigation. If
Auto
is selected and the transducer is capable, the data is shown.
Advanced Sonar Settings
To adjust advanced sonar settings, press
MENU
while viewing a sonar screen.
Range
—adjusts the range of the depth scale on the right side of the screen. Select
Auto
or, to adjust
manually,
Up
or
Down
.
Gain
—controls the sensitivity of the sonar receiver. Select
Auto
or, to adjust manually, select
Up
or
Down
. To see more detail, increase the gain. If the screen is cluttered, decrease the gain.
Frequency
—selects how the frequencies appear on screen (
200kHz
,
50kHz
, or
Dual
) when using a
dual frequency transducer.
Zoom
—zooms in to a section of the Full screen. The zoom is off (
No Zoom)
by default. Three other
options are available:
2x Zoom
—twice the magnification. Select
Up
,
Down
, or
Auto
to set the depth range of the
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