76 GPSMAP 392/398/492/498 Owner’s Manual
USING SONAR > SONAR PAGE
If Frequency is set to Dual, you can set the Gain separately for
each frequency (50 kHz and 200 kHz).
Color Gain
—ccontrols what colors are applied to the objects
on the screen. Auto (default) is the recommended setting. It
automatically sets the colors, based on your Auto Color Gain
setting. You can also set the Color Gain manually. If Frequency
is set to Dual, you can set the Color Gain separately for each
frequency (50 kHz and 200 kHz).
Whiteline—controls how the unit shows information about the
bottom type (hard or soft). With the Whiteline Off, the bottom
return shows as red and contains no information on bottom
hardness. With Whiteline set at Normal or 1-100%, the bottom
return becomes white with a red line, in the default color scheme,
indicating where the water meets the bottom. To turn the Whiteline
Off, press the ROCKER down until the setting bar is all the way at
the bottom of the range and reads Off.
Frequency—only appears when using a dual frequency transducer.
This allows you to choose a sonar operation frequency. You can
choose 200 kHz, 50 kHz or Dual frequency (to alternate between
the two frequencies).
UltraScroll/Scroll
—adjusts the rate at which the Sonar Pages
scroll from right to left. Ultrascroll™ (default) is used when you
select a scroll rate from 90% to 100%. Auto automatically adjusts
the scroll rate according to the boat’s speed.
Depth Line—adds a horizontal depth line across the screen that is
used to measure the depth of underwater objects. The depth of the
line appears on the right side of the line. Press up or down on the
ROCKER to control the position of the line on the Sonar Page. To
turn the Depth Line off, press the ROCKER up until the setting
bar is all the way at the top of the range and reads Off.
