Garmin 160C - Manual (Page 25)

Fishfinder 160C Owner’s Manual 21
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PPENDIX
> S
PECIFICATIONS
Understanding Sonar
This section is intended to help the novice user gain some
understanding of how the Fishfinder 160C operates and how it can
help improve fishing productivity.
To understand what the unit is displaying, it is important to have
a general knowledge of how the unit works and how it determines
what to display. Briefly described, the unit operates by transmitting
sound waves toward the bottom of a lake, stream, or seabed in a
cone-shaped pattern. When a transmitted soundwave strikes an
underwater object such as the bottom, a piece of structure, or a fish,
sound is reflected back to the transducer. The transducer collects the
reflected sound waves and sends the data to the unit to be processed
and displayed on the graph. The underwater data is displayed on
the graph in the order that it is returned: first returned—first on the
graph. The diagram to the right demonstrates this by showing an
underwater scene as it would be displayed on the graph. Generally
speaking, if the only thing between the transducer and the bottom
is water, the first strong return will come from the bottom directly
below the transducer. The first strong return sets the bottom level.
Weaker secondary returns provide the detailed data. Sonar returns
display as reds (strongest), then oranges (strong), yellows (medium),
greens (weaker), and blues (weakest).
That is a brief description of how your Fishfinder 160C operates.
The following pages show how this data can help you to improve
your fishing.
This fish is currently in a dead zone and is not detected by the
sonar. The fish is in the coverage area of the transducer, but
remember—the first strong return sets the bottom level. The fish
will eventually be detected when the first strong return sets the
bottom level below the fish.
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