Raymarine GPM400 Reference Manual page 56

Arriving at a waypoint
When the distance to the next waypoint in the route is less than that
specified for the arrival alarm radius (see
reaches the closest point of approach to the target (defined by a
line passing through the waypoint and perpendicular to the route
leg), a warning dialog is displayed and an alarm sounds (see
page 48).
When you acknowledge the alarm, the system selects the next
waypoint in the route and begins navigating to it.
Follow in reverse order
This option reverses the waypoint order (the last waypoint in the
route becomes the first) and renumbers the waypoints accordingly.
The route name moves to the reassigned first waypoint and then
the system automatically activates the reverse-follow route
function.
Advance waypoints
You can tell the system to ignore the next waypoint in your route,
and advance directly to the waypoint after it.
To skip the next waypoint
1. Highlight the route with the cursor, or press the GOTO softkey.
2. Press the ADVANCE WAYPOINT softkey.
Note: If the next waypoint is also the last in the route, pressing
ADVANCE WAYPOINT takes you to the first waypoint in the
route.
Cross-track error
Resetting the cross-track error (XTE) produces a new course from
your position to the target waypoint.
G-Series Reference Manual
This is useful if you find yourself off course and want to go straight
to your target, rather than get back onto the original track.
Although RESTART XTE causes your vessel to change course, it
page 194), or your boat
does not affect the saved route.
To restart cross-track error
1. With a route active, press the RESTART XTE softkey.
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