Using the Sonar PageWhen combined with a GSD 20 or GSD 21 Sounder Module, yourGPSMAP 496 becomes a powerful fishfinder/flasher with the SonarPage. If a GSD 20 or GSD 21 is attached, but the unit does notdetect a transducer, a “Sonar Turned Off” message appears acrossthe Sonar Page. If a GSD 20 or GSD 21 is not attached, the SonarPage only appears when the unit is in Simulator Mode.The middle of the page contains a right-to-left moving sonar imageof the water beneath your boat. Items appear as they pass under yourtransducer. Those items on the right side of the screen are closerto you than those on the left. Along the right side of the screen isan adjustable scale that reflects the depth of the area being shown.The top left corner shows the Adjustment Option, the depth, and thewater temperature.Sonar PageThe sonar returns show as red (strongest), then orange (strong),yellow (medium), green (weaker), and blue (weakest). The FishSymbols option allows you to view the actual sonar data, a fishsymbol or a combination of both. When the unit is set to Dual, theappearance of the fish symbols changes. Fish symbols from thecenter of the beam (200 kHz) are solid (or narrow arches), but thereturns from the edges of the beam (50 kHz) are hollow (or widearches).The Sonar Page can also be set to show a split screen view of azoomed portion of the sonar, bottom lock (screen scaled from thebottom up), or a combination of these options. For example, youcan choose to show dual frequency at a 2X zoom (Dual 2X) on onehalf and normal range dual frequency (Dual) on the other half. Thecurrent display mode is shown at the bottom of each sonar screen.136 GPSMAP 496 Owner’s ManualSETTING UP AND USING SONAR > U SING THE SONAR PAGE
