Structure.
Structure is defined as any object physically attached to the
bottom. The sonar configuration of the 350TX is optimized to give the most
accurate depiction of bottom structure possible. Grass, trees, stumps,
wrecks or other debris are accurately displayed, however the depiction of
these objects varies with boat speed and direction. The best way to learn to
interpret structure is to operate the 350TX over a variety of known
conditions and experiment with user functions to best represent those
conditions on-screen.
Surface Clutter.
Surface clutter is the layer of water near the surface that
is rich in algae and other growth, and often is aerated by wind or wave
action. This area of water interferes with sonar transmission and often
appears on-screen as regular clusters of individual dots near the “0” line.
Thermoclines.
Thermoclines are sharp differences in water temperature.
These are easily identified by the continuous nature of the return.
Second Returns.
When a sonar signal is reflected off the bottom back to
the transducer, there is often enough
energy left in the signal to be reflected
off the surface of the water back to the
bottom a second time. Second returns
appear as a slightly weaker bottom
representation exactly twice the depth
of the primary bottom return. The
second return is most likely to occur in
shallow water and in areas of relatively
hard bottom.
Fish ID.
The 350TX uses advanced
signal processing to further evaluate
any sonar return between the surface
and the bottom. For instance, a small
school of bait fish usually appears as a
dense cluster of individual dots. If the
return meets certain additional criteria,
a fish symbol will be assigned. There are three different size fish symbols
used to indicate the intensity of the sonar return. While signal intensity is a
good indicator of relative fish size, different species of fish have different
sonar characteristics, so it is not always possible to distinguish fish size
between varying species. The signal intensity is "normalized" for depth so
10
USING THE 350TX
WHAT YOU SEE ON SCREEN
Thermocline Second Return
