Humminbird 798c, Operation Manual

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9 What’s on the Side Imaging ® Display
Shadows result from a lack of reflected
sonar from a particular area, and can be
more valuable for interpretation than
the sonar reflected by the object itself.
Use shadows to help you see the image
in 3 dimensions, oriented in space. You
can gain insight into the actual shape of
an object, or the depth to which it has
sunk into the bottom, through shadows
on the display. Objects standing on the
bottom cast a sonar shadow. The longer
the shadow, the taller the object. Fish
also cast shadows. You can use the
shadow to interpret how close the fish is
to the bottom.
The water column shows the relative
depth of the water under the boat at a
given time. Variations in the width of
the water column show variations in
the distance to the bottom as the boat
passes over.
accurate interpretation of bottom contour and structure. For Side Imaging
®
, the
rock and gravel provide a clearer sonar return than mud and sand because of
better than downward slopes that face away from the transducer. You can find
allow for accurate interpretation of bottom contour and structure, including the
Side Imaging
®
Range - Images shown
on the right side of the screen are
located on the right side of your boat,
and images shown on the left side of
the screen are located on the left side
of your boat. In this picture, the sonar is
pinging 150 feet on each side.