Garmin GPS III Plus - Manual (Page 69)

Once a TracBack has been activated, the GPS III+ will take the track log currently
stored in memory and divide it into route segments, called ‘legs’. Up to 30 track log
waypoints (labeled ‘T###’, e.g. ‘T001’) will be created to mark the most significant
features of the track log in order to duplicate your path as closely as possible. To gain
the most benefit from the TracBack feature, keep the following tips in mind:
• Always clear the track log at the point you want to return to (boat ramp,
dock, trailhead, etc.)
• The ‘Record Mode’ on the Track Logs Page must be set to ‘Wrap’ or ‘Fill’.
• There must be at least two track log points stored in memory to create a
TracBack route.
• If there is not enough available memory to add more waypoints and create a
TracBack route, you will be alerted with a ‘waypoint memory full’ message. The
receiver will use the available waypoints to create a route with an emphasis on
the track log data closest to the destination. Also, existing TracBack waypoints
(‘T###’) that are not contained in routes will be erased to free more memory.
The GPS III+ will create new waypoints using the first available three-digit
number.
• If the Track Logs Page ‘Interval’ field is set to ‘Time’, the route may not follow
your exact path. (Keep the ‘Interval’ field set to ‘Resolution’ for best results.)
• If the receiver is turned off or satellite coverage is lost during your trip,
TracBack will draw a straight line between any point where coverage was lost
and where it resumed.
• If there are frequent changes in direction and distance in your track log, 30
waypoints may not accurately depict your exact path. The receiver will then
assign the 30 waypoints to the most significant points of your track log, and
simplify segments with fewer changes in direction.
A TracBack route contains a
series of waypoints labeled
‘T###’ that approximate your
previous route of travel.
‘Wrap’ will overwrite the old
track log data in memory,
once all memory has been
used. ‘Fill’ will record data
until memory is full, then
stop.
59
REFERENCE
TracBack Tips