BOTH INTERNATIONAL & INLAND While underway you sight a vessel displaying the day-shapes shown in illustration D006RR below. What action should you take?

Correct Answer: Option D — stay clear, the other vessel cannot get out of the way

Day-shapes depicting a ball between two balls or similar restricted maneuverability signals indicate a vessel constrained by its ability to maneuver under COLREG Rule 27. Other vessels must actively stay clear because this specialized unit cannot easily alter its course or speed.