Humminbird Single Beam 105SX Operation Manual page 11

USING THE 105SX
WHAT YOU SEE ON-SCREEN
Bottom Depiction Zero Line
When in Auto mode, the horizontal
line at the top of the screen is the
"zero line," representing the surface
of the water. Occasionally there is a
gap in this line. This gap indicates
the unit is updating the display even
if the bottom is not visible on-
screen, or if the bottom information
is not changing.
New sonar information appears on
the right side of the graphic area of
the display and moves to the left as
new information is displayed. The
105SX automatically selects the
Water Depth
Depth Range
appropriate depth range to show
the depth of water beneath the
Figure B
transducer. This range is selected so
the bottom representation is typically shown about 2 / down the display.
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Bottom. The graphic depiction of the bottom provides an effective tool for
understanding the composition of the
bottom. If the bottom is hard and
Surface Clutter Rocky Bottom
smooth, the bottom depiction is narrow
and dense. If the bottom is soft mud or
sand, the depiction will be thick and
less dense. This indicates much of the
signal is absorbed by the soft bottom. If
the bottom is rocky or rugged in
composition, the depiction is of varying
density and textured in appearance.
Wave action also affects the bottom
depiction. The information drawn is
a distance measurement, so if the
boat is moving up and down over
flat bottom, the bottom depiction
often appears in regular variations
Soft Bottom Hard Bottom
that match wave timing.
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