Garmin GPSMAP 392, 398, 492, 498 Owner's Manual

Also see for GPSMAP 392, 398, 492, 498: Quick reference guide Specifications

Contents

76 GPSMAP 392/398/492/498 Owner’s ManualU SING SONAR > SONAR PAGEIf Frequency is set to Dual, you can set the Gain separately foreach frequency (50 kHz and 200 kHz).Color Gain—ccontrols what colors are applied to the objectson the screen. Auto (default) is the recommended setting. Itautomatically sets the colors, based on your Auto Color Gainsetting. You can also set the Color Gain manually. If Frequencyis set to Dual, you can set the Color Gain separately for eachfrequency (50 kHz and 200 kHz).Whiteline—controls how the unit shows information about thebottom type (hard or soft). With the Whiteline Off, the bottomreturn shows as red and contains no information on bottomhardness. With Whiteline set at Normal or 1-100%, the bottomreturn becomes white with a red line, in the default color scheme,indicating where the water meets the bottom. To turn the WhitelineOff, press the ROCKER down until the setting bar is all the way atthe bottom of the range and reads Off.Frequency—only appears when using a dual frequency transducer.This allows you to choose a sonar operation frequency. You canchoose 200 kHz, 50 kHz or Dual frequency (to alternate betweenthe two frequencies).UltraScroll/Scroll—adjusts the rate at which the Sonar Pagesscroll from right to left. Ultrascroll™ (default) is used when youselect a scroll rate from 90% to 100%. Auto automatically adjuststhe scroll rate according to the boat’s speed.Depth Line—adds a horizontal depth line across the screen that isused to measure the depth of underwater objects. The depth of theline appears on the right side of the line. Press up or down on theROCKER to control the position of the line on the Sonar Page. Toturn the Depth Line off, press the ROCKER up until the settingbar is all the way at the top of the range and reads Off.