BOTH INTERNATIONAL & INLAND By day, you sight a vessel displaying three shapes in a vertical line. The top and bottom shapes are balls, and the middle shape is a diamond. It could be a __________.

Correct Answer: Option C — vessel engaged in replenishment at sea

Pursuant to COLREGS Rule 27(b), a vessel restricted in her ability to maneuver when engaged in a towing operation such as replenishment at sea, which severely restricts the towing vessel and her tow in their ability to deviate from their course, exhibits three shapes in a vertical line: balls at the top and bottom with a diamond in the middle.