Thin or no Grayline
Wider Grayline
At left, little Grayline indicates a soft bottom, probably sand or mud.
At right, the wider Grayline indicates a harder, rocky bottom.
Press UP ARROW to increase the level or press DOWN ARROW to decrease it. The percentage of Grayline in use shows in this menu. Echoes scrolling onto the screen will also show the effects of the Grayline change. If you reach the maximum or minimum level, a tone sounds alerting you to the limits. Press PWR to clear the menu.
FISH I.D.
The Fish I.D. feature identifies targets that meet certain conditions as fish. The microcomputer analyses all echoes and eliminates surface clutter, thermoclines and other signals that are undesirable. In most instances, remaining targets are fish.
The Fish I.D. feature displays symbols on the screen in place of the actual fish echoes. There are three symbol sizes: small, medium and large. These show the relative size between targets. In other words, it displays a small fish symbol when it thinks a target is a small fish, a medium fish symbol on a larger target and so forth.
Fish 
arches 
Fish I.D. symbols
At left, underwater scene in normal fish arch mode. Right, Fish I.D.
menu with the feature turned on.
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