Garmin GPS III A Owner's Manual

Also see for GPS III: Declaration of conformity Quick guide Owner's manual Owner's manual

Units SettingsDistance & Speed lets you select the desired units of measure for distance and speedreadouts in ‘Nautical’, ‘Statute’ or ‘Metric’ terms.Heading lets you select the reference used in calculating heading information. You canselect from ‘Auto Mag Var’, ‘True’, ‘Grid’ and ‘User Mag Var’. ‘Auto Mag Var’ providesmagnetic north heading references which are automatically determined from your currentposition. ‘True’ provides headings based upon a true north reference. ‘Grid’ providesheadings based on a grid north reference (and is used in conjunction with the grid posi-tion formats described on page 74). ‘User Mag Var’ allows you to specify the magneticvariation at your current position and provides magnetic north heading references basedupon the variation you enter.Altitude lets you select altitude readouts in ‘Feet’ or ‘Meters’.To select a units setting:1. Highlight the desired field and press ENTER to display the available options.2. Select the desired option and press ENTER.3. If ‘User Mag Var’ is selected in the ‘Heading’ field, highlight the heading reference field (immed-iately to the right) and press ENTER. Enter the magnetic variation at your current position usingthe rocker keypad and press ENTER.WARNING: If ‘User Mag Var’ is selected, you must periodically update the magnetic vari-ation as your position changes. Using this setting, the GPS III will not automatically cal-culate and update the magnetic variation at your present position. Failure to update thissetting may result in substantial differences between the information displayed on yourGPS III and external references, such as a magnetic compass.Select nautical, statute ormetric units of measure fromthe ‘Units’ settings.The ‘User Mag’ option allowsyou to define the magneticvariation for your area. ‘AutoMag Var’ is the preferred set-ting in most cases.70REFERENCESetup Menu: Units#!