Position PageThe GPS 40’s position page shows you where you are,what direction you’re heading and how fast you are going(up to 99.9 mph), and is most useful when you are travel-ling without an active destination waypoint. A graphic com-pass tape at the top of the page displays your cardinal head-ing (while you’re moving), with your current track andspeed over the ground indicated below. The rest of the pageshows your present position in three dimensions (latitude,longitude and altitude). The units of measure for speed,distance, position and altitude are all user-selectablethrough the navigation setup menu (see page 47). The12/24 hour clock and time offset options are available fromthe system setup menu (see page 46).Trip OdometerThe position page also features a resettable trip odome-ter to measure the total distance travelled while navigating.To reset the trip odometer:1. Press the D key until the trip field is highlighted.2. Press E, followed by L.3. Press E to finish.Altitude DisplayWhen the GPS 40 is acquiring satellites or navigating inthe 2D mode, the last known altitude will be used to com-pute your position. If the altitude shown is off by severalhundred feet, you can manually enter your altitude forgreater accuracy. Note that GPS altitudes can fluxuate dueto errors.1. Press the D key until the altitude field is highlighted.2. Press E to begin entry of your altitude.3. Use the U and D keys to enter a value in each char-acter field, and use L and R keys to move to the nextcharacter position.4. Press the E key to confirm the altitude.20ReferencePosition PageThe speed displayed on theposition page may fluctuateat slow speeds (or whenyou’re standing still).To reset the trip odometer,highlight the trip field andpress ENTER. Use theLEFT arrow key to clear thedistance field, and pressENTER to confirm.