Every boat, and every wait (click a boat for details; it is highlighted in the animation and the chart)
Make something go wrong
Close a lock(unplanned maintenance)
Lock from to
Delay a boat(it turns up later)
Boat by min
Add a closure or a delay, then press Re-plan. The page re-solves the canal right here in your browser with the same solver that made the original plan.
What changed
Nothing yet. After re-planning, this lists the new score and every boat that got later or earlier, and why.