Bait school 
Fish
arches
Sensitivity at 71 percent (left). Sensitivity at 100 percent (right).
To change the Grayline level:
1.Press MENU until the GRAYLINE control bar appears.
2.Press ↑ to increase the level of Grayline or press ↓ to decrease it. If you reach the maximum or minimum level, a tone will sound. Press PWR to clear the menu.
Thin or no Grayline→
Wider Grayline→
A small amount of Grayline indicates a soft bottom (left), probably sand or mud. More Grayline indicates a harder, rocky bottom (right).
Chart Speed
The rate that echoes scroll across the screen is called the chart scroll speed. The default for this unit is the maximum, 100 percent.
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