Humminbird Wide One - Manual (Page 24)

Range
The Wide One Hundred adjusts the depth range automatically,
so the bottom return is displayed at the bottom 1/3 of the
display. This leaves the top 2/3 to display anything between the
surface and the bottom. As your boat moves over deeper or
shallower water, the unit adjusts the depth range of the display
to keep the bottom return in the same general area on the
screen.
You may, however, choose to control this range adjustment
manually. By pressing ENTER, you can select manual
operation, meaning the unit will no longer adjust the depth
range automatically. The depth range selected is controlled by
the UP and DOWN arrow buttons. The depth ranges are 015',
30', 60', 120', 180', 240', 360', 480', & 600'.
If you alter the depth range, Manual operation is automatically selected and the area beneath the
bottom will no longer be blackened-in.
This feature is valuable if you are only interested in targets near the surface. The Wide One
Hundred will always display the digital depth of the water, regardless of whether the bottom is
shown on the selected depth range.