58 GPSMAP 2106/2110 Owner’s ManualM AIN MENU > SYSTEM TABSonar Alarms*Use the Sonar sub tab to set sonar alarms, including shallow or deep water,water temperature, and fish.• Shallow Water/Deep Water—sets an alarm to sound when you enteran area of specified depth that is too shallow or too deep. You must bereceiving sonar data for this function to work.• Water Temperature—sets an alarm to sound when the transducer reportsa temperature either above, below, inside, or outside the specified values.• Fish —sets an alarm to sound when the unit detects a fish of the specifiedsymbols.*You must be receiving NMEA sonar data or using a GSD 20, GSD 21, or GSD 22 for thesonar alarms to function.System TabThe System tab consists of five sub tabs:General, Units, Time, Comm, andUpdate.General Sub TabUse the General sub tab to control system settings for system mode, speed filter,automatic backlight, beeper, language, simulator controls, restore factory defaultsettings, and to view the software version.The following settings and options are available:• System Mode—select Normal (normal navigation) or Simulator (forpractice only). For more information about Simulator Mode, see “SimulatorMode” on page 8.• Speed Filter—averages speed readings. Select Off, Auto (automaticallycontrols filtering), or On (allows you to enter a value from1 to 255 seconds).• Automatic Backlight—automatically adjusts the display brightness to aspecified level at sunrise and sunset. You can specify offset minutes forbefore sunrise and after sunset.
