Furuno FSV-30 Operator's Manual page 105

Upward + downward looking net recorder display (ES2 mode)
The marks and indications which appear on the downward looking display are
also common to the upward + downward looking display.
W
Echo Sounder 2 display (Upward + downward looking display)
N
S
4. ECHO SOUNDER MODE
NUMERIC/GRAPHIC
DATA DISPLAY
60
30
E
0
30
60
Ground rope
Upward
Looking
Picture
0
Downward
Looking
Picture
4-5