78 GPSMAP 292/298 Owner’s Manual
USING SONAR > SONAR TAB OPTIONS
Auto Color Gain—controls what colors are applied to the objects
on the screen. Color DCG is based on depth and makes it easier to
spot subtle changes in bottom conditions or fish sizes. DynaColor
(default) represents the latest in sonar data presentation and is
recommended for all applications. The presentation is based on
bottom strength. It makes the bottom and the fish easier to see and
requires fewer adjustments.
Automatic Gain Level—controls the aggressiveness of the Auto
Gain. The higher the setting, the greater the number of targets
appear on the screen. The lower the setting, the less clutter on the
screen. The settings are Low, Medium (default), and High.
Automatic Scroll Speed Limit—automatically adjusts the Scroll
rate (see page 74) with the speed of your vessel. Entering your
maximum cruising speed produces a 100% scroll rate when you
reach that speed. One half of that speed produces a 50% scroll rate,
and so on. The default is 30.0 kt.
Transducer Type
—allows you to specify what type of transducer
you are using.
Calibrate Water Speed—this appears only if you are using a
speed-capable transducer/sensor. Calibration is required to ensure
that the Water Speed shown on your unit is accurate. The unit
automatically uses GPS ground speed for comparison on the
calibration. If a GPS ground speed is not available, use either your
boat’s speedometer reading (not always accurate) or a stopwatch
to determine your speed over a certain distance (distance / time =
speed). It is recommended that the calibration take place in water
having little or no current.
