GPSMAP 496 Owner’s Manual IntroductIon > tAble of contentsBasic Operation in Marine Mode ......................................86Marine Mode Page Sequence ............................................... 86Navigating in Marine Mode ................................................... 87Marine Mode Pages and Features....................................88Map Page ................................................................................ 88Compass Page ....................................................................... 89DSC ......................................................................................... 91Main Menu ..........................................................................96GPS Tab .................................................................................. 96Flights Tab.............................................................................. 96Route Tab ............................................................................... 97Points Tab .............................................................................. 97Track Tab ................................................................................ 97Sonar Tab ............................................................................... 98Aircraft Tab............................................................................. 98Alarms Tab ............................................................................. 99Celestial Tab......................................................................... 102Message Tab ........................................................................ 106Display Tab........................................................................... 107Sound Tab ............................................................................ 108Setup Tab ............................................................................. 109Location Sub Tab................................................................. 114Setting Up and Using Sonar ...........................................119Showing Sonar on the Map Page ....................................... 119Using the Sonar Page ......................................................... 120Setting Up the Sonar Page ................................................. 124Understanding Sonar .......................................................... 127Viewing the Sonar Temperature Tab .................................. 130VHF Comm .......................................................................131Appendix ..........................................................................132Specifications ...................................................................... 132Optional Accessories .......................................................... 133Installation Information ....................................................... 134Declaration of Conformity (DoC) ....................................... 138Learning About GPS ........................................................... 139LORAN TD Setup ................................................................. 140Map Datums and Location Formats .................................. 142Digital Selective Calling (DSC) ........................................... 143Jeppesen Database Information ........................................ 144Messages ............................................................................. 145Data Field Options ............................................................... 147License Agreement and Warranty...................................... 149Index .................................................................................151