8 GPS 158 Owner’s ManualSystemBeeper: Sets when the beeper sounds�Speed Filter: Sets the speed filter�Language: Sets the system language�System Information: Displays the Unit ID and other information�UnitsPosition Format: Sets the position values to the selected format�Map Datum: Sets the map datum to the selected format�Heading: Sets the heading value to the selected format�Distance, Speed and elevation: Sets the values to the selected format�Depth: Sets the depth values to the selected format�CommunicationsSets the serial data format and transfer mode� Contact your Garmin authorizeddealer to use transfer mode, which is for software updates�NMeA® Out SentencesGPRMC, GPRMB, GPGGA, GPGSA, GPGSV, GPGLL, GPBOD, GPBWC, GPVTG,GPXTE, PGRME, PGRMZ, PGRMM, GPRTE, GPWPL, GPAPBNMeA In SentencesDPT, DBT, MTW, VHW, WPLAlarmsSystemClock: Sets an alarm to sound at a specified time of day�Power: Sets an alarm to sound when the voltage is below the voltage entered�DGPS: Sets an alarm to sound when the device is using DGPS�Accuracy: Sets an alarm to sound when the GPS accuracy drops below thespecified threshold�NavigationAnchor Drag: Sets an alarm to sound when your vessel drifts farther than thespecified distance while at anchor�Arrival: Sets an alarm to sound when you arrive at your destination�Off Course: Sets an alarm to sound when your boat is farther off course than thespecified distance�