Raymarine C140w - Manual (Page 153)

Clutter / Background noise
The fishfinder picture may be impaired by echoes received from
floating or submerged debris, air bubbles or even the boats
movement. This is known as ‘background noise’ or ‘clutter’ and is
controlled by the gain modes. The system will automatically control
the gain settings according to the depth and water conditions. You
can however adjust the gain settings manually if you prefer.
12.3 Fishfinder presets
The fishfinder provides you with four preset configurations available
on the fishfinder toolbar. These enable you to quickly select
appropriate settings tailored for various situations.
Each preset has been configured to provide the best operating
parameters for the fishfinder. However, it is possible to manually
adjust the presets if necessary. The four presets are:
• Single — this preset provides quick access to a single-frequency
configuration, suitable for general fishing conditions.
• Dual — this preset provides a dual frequency configuration.
You can either display two different frequencies at the same
time in one window, or display one frequency at full-screen on
your master display and the other frequency at full-screen on an
additional networked display.
• Shallow — this preset opitimizes the fishfinder display for shallow
waters.
• Deep — this preset opitimizes the fishfinder display for deep
waters.
Display modes
When using presets, you can either select the relevant preset and
start using the default configuration immediately, or you can adjust
the preset to your needs using the display modes:
• Zoom
• Bottom Lock
• A-Scope
Any changes you make to a preset are retained when you switch
off the power to your multifunction display.
Using the fishfinder 153