Grayline scroll bar.
If you have two signals of equal size, one with gray and the other with- out, then the target with gray is the stronger signal. This helps distin- guish weeds from trees and fish from structure.
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).
Grayline is adjustable. Since Grayline shows the difference between strong and weak signals, adjusting the sensitivity may also require a different Grayline level.
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