Fish
arches
These figures show results of different sensitivity levels on the same location. Fig. 1: Sensitivity at 98 percent, determined by Auto Sensitiv- ity. Typical of full auto mode. Fig. 2: Sensitivity set at 71 percent. Fig.
3: Sensitivity set at 47 percent. Fig. 4: Sensitivity set at 100 percent.
Grayline®
Grayline→ lets you distinguish between strong and weak echoes. It allows you to tell the difference between a hard and soft bottom. For ex- ample, a soft, muddy or weedy bottom returns a weaker signal which is shown with a narrow line or no gray line at all. A hard bottom returns a strong signal, which will be displayed as a wide gray line.
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 distinguish weeds from trees on the bottom or fish from structure.
Grayline is adjustable. Since Grayline shows the difference between strong and weak signals, adjusting the sensitivity may also require a different Grayline level. The level chosen by the sonar unit at power on
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