54 GPSMAP 400/500 Series Owner’s ManualConfiguring the Chartplotterwater Temp—set an alarm to sound when the transducer reportsa temperature that is 2°F (1.1°C) above or below the specifiedtemperature.fish—set an alarm to sound when the unit detects a suspendedtarget of the specified symbols.—sounds an alarm for all fish sizes.—sounds an alarm for medium and large fish only.—sounds an alarm for large fish only.Setting Weather AlarmsNOTE: You must have a subscription to XM WX Weather anda connected Garmin XM WX weather receiver to view weatherinformation (page 68).1. From the Home screen, select Configure > Alarms > Weather.2. Turn the following alarms on or off: marine, tornado, severestorm, flood, or flash flood.Setting the Total Fuel Onboard AlarmYou can configure your chartplotter to sound an alarm when the totalamount of remaining onboard fuel reaches the specified level.NOTE: To receive fuel-level information, your unit must beconnected to an external fuel sensor, such as the Garmin GFS 10.To enable the Total Fuel Onboard alarm and set the fuelalarm level:1. From the Home screen, select Configure > Alarms > Fuel >Total Onboard > On (or Off).2. If you select On, use the rocker to indicate the fuel level atwhich the alarm should sound.Configuring My BoatTo configure settings for your boat, from the Home screen, selectConfigure > My Boat.Keel Offset—compensates for the surface reading for the depth ofa keel, making it possible to measure depth from the bottom of thekeel instead of from the transducer location. Enter a positive numberto offset for a keel. You can enter a negative number to compensatefor a large vessel that may draw several feet of water.To adjust the Keel Offset:1. If the transducer is installed at the water line, measure thedistance from the transducer location to the keel of the boat.Enter this value in step 3 as a positive number.If the transducer is installed at the bottom of the keel, measurethe distance from the transducer to the water line. Enter thisvalue in step 3 as a negative number.2. From the Home screen, select Configure > My Boat > KeelOffset.