Furuno NAVNET 1823C - Manual (Page 162)

4. VIDEO SOUNDER OPERATION
4-16
4.9 White Marker
The white marker functions to display a particular echo color in white. For
example, you may want to display the bottom echo in white to discriminate fish
echoes near the bottom.
1. Press the [MENU] key.
2. Press the SOUNDER MENU soft key.
3. Select WHITE MARKER, then press the EDIT soft key to open the white
marker window.
WHITE MARKER
▲
OFF
▼
White marker window
4. Use the trackball to select the color to display in white. As you use the
trackball, the number in the white marker window changes, the white marker
on the echo strength bar shifts and the selected echo color is displayed in
white.
←
White marker shows
color currently
displayed in white.
Color bar (16 color) when white marker function is active
5. Press the RETURN soft key followed by the [MENU] key to close the menu.
To turn the white marker function off, display “OFF” in the white marker window.