Garmin Fishfinder 160 Owner's Manual

Also see for Fishfinder 160: Specifications

Garmin Fishfinder 160 Owner's Manual Manual pdf 39 page image

31On the Water31On the WaterUnderstanding the ChartWhitelineThe Fishfi nder 160 can help you to determine if the bottom is hardor soft. When the sonar soundwaves are reflected back by the bottom, ahard bottom will return a stronger signal than a soft bottom. The strongerbottom return, the wider the bottom layer is displayed. The unit usesthe whiteline function to make this bottom layer information easier todistinguish.When viewing the display without Whiteline active, the bottom returnis black. While you can make some determination of the bottom type,the black return makes this more difficult. With the whiteline active thebottom return appears layered in shades of gray and black and makesdetermining the bottom type easier and more reliable. Example 3 showsthe bottom return with and without the whiteline activated.Whiteline Turned Off Whiteline ActiveHardBottomSoftBottomWhitelineExample 3.Whiteline can also help you to determine the typeof bottom structure that is displayed on chart. Bydetermining the hardness of the structure you canmake a better informed decision on the type ofstructure.Structure is hard, probably arock or stumpStructure is soft, probably amud pile