Chapter 6: The Fishfinder 131
Boat speed
The fishfinder’s reading of the bottom changes as your speed changes. Slower
speeds return flatter, more horizontal marks; as your speed increases, the image will
tend to thicken and arch, until at high speeds the bottom resembles a double line on
the fishfinder display.
Depth
As sea depth increases, signal strength decreases, resulting in a lighter on-screen
image of the bottom.
Object size
The larger an object is, the stronger its return on the fishfinder display will be.
However, the strength of return from fish depends upon the species’ swim bladder,
rather than the body size.
Background noise
The fishfinder readout can be affected by weak echoes from floating or submerged
debris, air bubbles, or by your boat’s movements.
This background noise is also known as clutter, and the E-Series system
automatically adjusts sensitivity to it based on sea depth and water conditions. You
can, however, set the sensitivity manually by using the gain modes (gain, color gain
and TVG).
Transducer frequency
• Lower frequencies scan a wide area and penetrate water well. Use these
settings if you want a large coverage beneath your boat or if you are in deep water.
• Higher frequencies (200 Khz) scan a narrow area but produce more detail,
especially at high boat speed. They are most useful in shallower waters (up to 1000
feet).
Various frequencies may be available on your system, depending on the transducers
fitted to your vessel.
Viewing single or dual frequencies
If the preset you are using includes two frequencies, you can use one fishfinder
window to view both frequencies or just one. You can then send the second
frequency to a fishfinder window on a second monitor, enabling you to view both
frequencies at full screen.
6.6 Display mode settings
When a fishfinder preset is selected, its softkey label changes to ADJUST. Pressing
this key allows you to configure the display mode settings to suit your requirements.
(Changes to the display mode are saved with the preset at power-off.)
81244_4.book Page 131 Thursday, January 31, 2008 1:53 PM
To Next Page
Loading...
