How Are Targets Displayed - Raymarine C-Series Reference Manual

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How are targets displayed?

When a target is detected, it is displayed on screen as a mark.
What factors influence how targets are displayed?
The shape and size of this mark is influenced by a combination of factors:
Boat speed
The shape of the target changes along with your speed. Slower speeds return flatter,
more horizontal marks. As your boat's speed increases, the target will tend to thicken
and arch slightly; until at fast speeds the mark resembles a double vertical line..
The depth of the target
The closer the target to the surface the larger the mark on screen.
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 General Operation and System Setup).
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.
What factors can impair 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
C-Series Display Reference Manual
Target
depth
Target