Humminbird 998c SI - Manual (Page 125)

115 Sonar Menu Tab
Color Bar
Settings: Off, On, Default = On
Color Bar allows you to display or suppress the display of the color bar
shown in the full screen Sonar View.
Temperature Graph
(Sonar View only, with Temperature input)
Settings: Off, On, Default = On
Temperature Graph allows you to display or suppress a water temperature
graph over the main Sonar View to show temperature changes correlated to
recent sonar history.
Down Imaging Beam Width
(Advanced)
Settings: Narrow, Medium, Wide; Default = Wide
Down Imaging Beam Width controls the width of the beam (side to side)
for the Down Imaging™ View and sets the amount of information shown on
the display.
To see only the data directly under your boat, select Narrow. Medium reveals
more information, while Wide displays the maximum information available
from the Down Imaging™ beam width.