Mark series units have a monochrome display, so wide bands of gray indicate a hard sonar return, while softer returns are shown as dark, narrow areas.

Auto Sensitivity

Keeps sensitivity at a level that works well under most conditions, reducing the needs for adjust- ments. Auto Sensitivity is turned on by default.

NOTE: You can make minor (+/-4%) changes to sensitivity with Auto Sensitivity turned on. You will have to turn it off to make significant adjustments.

Depth Range

Sonar

range. If you select too shallow a depth range the unit will not be able to lock onto the bottom.

Custom Range — Upper and Lower Limits (Advanced Mode only)

Used to select the upper limit and lower limit of a section of the water column. That allows you to view a section of the water column that does not include the water surface. Upper and lower limits must be at least 6.5 ft (2m) apart.

Custom range menu

Selects the deepest range shown on the display. Range settings display the section of the water column from the water surface to the selected depth

NOTE: When using a custom range, you may not receive any digital depth readings, or you may receive incorrect depth information.

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