Eagle FISHMARK 320 Installation And Operation Instructions Manual page 22

Transducer mounted on trolling motor, side view.
TRANSDUCER ORIENTATION AND FISH ARCHES
If you do not get good fish arches on your display, it could be because
the transducer is not parallel with the ground when the boat is at rest
in the water or at slow trolling speeds.
Partial fish arches
Transducer aimed
Transducer aimed
too far forward
too far back
Full fish arch
Proper transducer angle
Transducer angles and their effects on fish arches.
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