Factors Impairing A Fishfinder Picture; Seeing A Live Image - Raymarine E120W Reference Manual

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The depth of individual targets can be displayed by switching on the Target
Note:
Depth ID in the Fishfinder Setup Menu. The number of target depths displayed is influ-
enced by the fish alarm sensitivity level (see page 267).
The size of the target
The larger the target, the larger the return on the fishfinder display. The size of a fish
target is however dependent upon the size of the fish's swim bladder rather than its
overall size. This swim bladder will vary in size between different breeds of fish.
The frequency of the transducer
The same target will appear differently when the transducer frequency is changed. The
lower the frequency the broader the mark.

Factors impairing a fishfinder picture

Although weaker than the fish or bottom echoes, your fishfinder picture may be
impaired by echoes received from floating or submerged debris, air bubbles or from
your boat's movements. This is known as background noise or clutter and is controlled
by the gain modes (gain, color gain and TVG). Raymarine recommends that you allow
your system to automatically control the ideal sensitivity level based on depth and
water conditions. You can however adjust these settings manually if you prefer. For
more details, please refer to

Seeing a live image

The standard fishfinder display shows a historical record of fishfinder echoes. If
required, you can display a live image of the bottom structure and the fish directly
below the transducer by using the A-Scope feature. The width of the bottom covered
by the A-Scope is indicated at the bottom of the window. A-Scope provides a more
precise and easier to interpret indication of the target strength.
E-Series Networked Display Reference Manual
page 6- 138
.
Target
depth
Target