Raymarine C140w Fish Finder User Manual


 
It is also possible that the sound waves are making two complete
trips – hitting the seabed, bouncing off the vessel, then reecting
off the seabed again. This can happen if the water is shallow, the
seabed is hard, or the gain is set high.
Factors inuencing the sonar display
The quality and accuracy of the display can be inuenced by a
number of factors including vessel speed, depth, object size,
background noise and transducer frequency.
Vessel speed
The shape of the target changes along with your speed. Slower
speeds return atter, more horizontal marks. Higher speeds cause
the target to thicken and arch slightly, until at fast speeds the mark
resembles a double vertical line.
Target depth
The closer the target to the surface, the larger the mark on screen.
Note: The depth of individual targets can be displayed by
switching on the Target Depth ID in the shnder setup menu.
The number of target depths displayed is inuenced by the sh
alarm sensitivity level.
Water depth
As sea depth increases signal strength decreases, resulting in a
lighter on-screen image of the bottom.
Size of the target
The larger the target, the larger the return on the shnder display.
The size of a sh target is also dependent upon the size of the sh’s
swim bladder rather than its overall size. The swim bladder varies in
size between different breeds of sh.
Transducer frequency
The same target will appear differently when the transducer
frequency is changed. The lower the frequency the broader the
mark.
152 C-Series Widescreen user reference