Furuno FCV-1200L Operator's Manual page 60

GRAPH WIDTH
Selects the width of sonde water temperature graph; 1/4 of the screen or 1/2 of the screen.
Note: When turning on both of sonde water temperature graph and A-scope, 1/2 is not available.
GRAPH RESET
Select ON to reset the graph.
3-12
Scale (5 C)
Display Range(12 C)
10 15 20
0 5 10
Surface
Net sonde water temperature graph (SURFACE/BOTTOM)
Scale shifts with
temperature
15 20 25
5 10 15
Bottom