Garmin GPSMAP 168 Sounder - Manual (Page 70)

59
Reference
TracBack Navigation
To activate a TracBack using the NAV/MOB key:
1. Press the NAV/MOB key, then highlight the ‘Follow Track’ option and press ENTER/MARK.
2. Highlight the track you wish to follow and press ENTER/MARK.
3. Choose either ‘Original’, which will navigate you from the end to the start of your trip, or ‘Reverse’,
which will navigate you from the start to the end of your trip and press ENTER/MARK.
Once a TracBack has been activated, the GPSMAP 168 Sounder will take the track log currently
stored in memory and divide it into segments called ‘legs’. Up to 30 temporary ‘turns’ will be created
to mark the most signifi cant features of the track log in order to duplicate your exact path as closely as
possible. To get the most out of the TracBack feature, remember the following tips:
• Always clear the track log at the point that you want to go back to (dock, etc.).
• The ‘Record Mode’ option on the track log setup page must be set to ‘Fill’ or ‘Wrap’.
• There must be at least two track log points stored in memory to create a TracBack route.
• If the track log interval is set to the ‘Time’ option, the route may not follow your exact path (keep the
interval set to ‘resolution’ for best performance) see page 71.
• If the receiver is turned off or satellite coverage is lost during your trip, the TracBack will draw a
straight line between any point where coverage was lost and where it resumed.
• If your track log’s changes in distance and direction are too complex, 30 waypoints may not mark
your path accurately. The receiver then assigns the 30 waypoints to the most signifi cant points of
your track, and simplifi es segments with fewer changes in direction.
To stop TracBack navigation:
1. Press the NAV/MOB key, highlight ‘Stop Navigation’ and press ENTER/MARK.
2. Choose either ‘Yes’ or ‘No’ and press ENTER/MARK to confi rm.
For more information on setting up the Track options and saved tracks, see pages 70-71.
Default
Track
name
Check this box to display track
Additional
options Total
Distance
Total
number
of points
You must fi rst save a track before
using the ‘Follow Track’ option.
168 Manual Part 2.indd 59 11/18/2002, 3:37:52 PM