Noise Filter (Advanced); Max Depth (Advanced); Water Type (Advanced) - Humminbird 698ci HD SI Combo Operation Manual

Noise Filter adjusts the sonar Noise Filter to limit interference on the display
from sources such as your boat engine, turbulence, or other sonar devices.
The Off setting removes all filtering. Low, Medium, High 1, High 2, and High 3
settings add progressive filtering of the sonar returns. High 1, High 2, and High
3 are useful when there is excessive trolling motor noise, but in some deep
water situations, the High settings may actually hinder your unit's ability to find
the bottom.
Max Depth controls the maximum depth of operation. When Max Depth is set
to Auto, the Fishfinder will acquire bottom readings as needed (within the
capacity of the unit). When Max Depth is set to match your fishing maximum
depth, your Fishfinder will not attempt to acquire sonar data below that depth,
so more detail will be shown on the screen.
NOTE: If the bottom is deeper than the Max Depth setting, the digital depth
readout will flash, indicating that the Fishfinder cannot locate the bottom.
Water Type configures your unit for operation in fresh or salt water. In salt water,
you can also choose the shallow or deep setting. The Water Type menu option is
available when User Mode is set to Advanced (see Main Menu: User Mode).
Noise Filter
(Advanced)
Settings: Off, Low, Medium, High 1, High 2, High 3;
Default = Low
Max Depth
(Advanced)
Settings: Auto to 1500 feet, Auto to 500 meters
(International Models only); Default = Auto
Water Type
(Advanced)
Settings: Fresh, Salt (shallow), Salt (deep); Default = Fresh
141 Sonar Menu Tab