Another use of the Sensitivity menu is to select the bottom representation. The Wide Vision normally displays a variable Structure ID bottom, which can allow experienced users to determine the texture or relative hardness of the bottom. For simplicity, you can select a black bottom using the ENTER button. This blackens in the display below the bottom for easiest recognition of the bottom location, even from a great distance.
Range
The Wide Vision 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.
However, you may 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. Ranges of