This function can toggle on/off a segment of a course leg or an Out-of-Bounds frame line.  Two corner points delimit a segment, one at either end. 

When you want to cut a section out of a course leg you must first create a segment by adding two corner points to delimit the segment, then toggle off the segment between the two corner points.  This is a reversible process, as the segment can be toggled on again, and/or the corner points can be deleted.

1. Click the Toggle Segment button
2. Select the course leg in question by clicking the mouse on it.
3. Click the segment to toggle it off/on

The Scissors tool can cut a fixed length section of a course leg.