Garmin GPSMAP 3010C - Manual (Page 91)

GPSMAP 3006C/3010C Owner’s Manual 3
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General Sub Tab
Use the General sub tab to select the water type, depth number, automatic scroll
speed limit, scale, keel offset, and transducer type. The available General sub tab
options are as follows:
• Auto Gain—controls the aggressiveness of the Auto Gain when the Gain
option is set to Auto. 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.
• Auto Color Gain—controls what colors are applied to the objects on the
screen when the Color Gain option is set to Auto. 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 Scroll Speed limit—automatically adjusts the scroll rate 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.
• Keel Offset—allows you to offset the surface reading for the depth of a
keel. This makes it possible to measure depth from the bottom of your keel
instead of from a transducer’s location near the water line. Enter a positive
number to offset for a keel. You can also enter a negative number to
compensate for a large vessel that may draw several feet of water, requiring
the transducer to be submerged if you want to measure from the water line.
The Keel Offset is reflected in the depth reading.
Transducer at surface.
Enter (+) a postve
number to show depth
from bottom of keel.
Transducer at bottom of keel.
Enter (-) a negatve number to
show depth from surface.
• transducer type—allows you to specify what type of transducer you are
using, either Dual Beam or Dual Frequency.
• Calibrate Water Speed—this is available 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
the GPS ground speed, if it is available, 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 you
calibrate in water having little or no current.