Moving obstacle · once a round
The Sweeping Arm — How to Avoid Being Knocked Off Line
A circle a little past halfway up the hole. A ball that stops inside it is swept sideways, often into rough or a bunker.
What it is
One hole per round has a sweeping arm: a rotating bar inside a marked circle placed a little past halfway up the hole, right on the line of play. Any ball that comes to rest inside the circle is struck and moved sideways around the circle’s edge.
Where the ball goes
The arm pushes the ball a fixed distance — very roughly 30 to 50 yards depending on the hole’s length — along the direction the bar is sweeping. Where it ends up depends on where it stopped inside the circle, and it frequently finishes in rough, deep rough or a bunker. It does not cost a penalty stroke by itself.
Flying over it
Only the final resting position counts, so a ball that flies over the circle or rolls through it and stops beyond is completely unaffected. That makes the arm a question of where you stop, not where you land.
How to play it
Either lay up comfortably short of the circle, or carry far enough that rollout takes the ball past it. Landing just in front of the circle is the worst choice, because the roll will often end inside it. On the approach, check the circle before choosing a club that might come up short.