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. Which vessel are you observing?

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

Rule 27(b)(iii) defines the day shapes for a vessel restricted in her ability to maneuver as three shapes in a vertical line, with the highest and lowest being balls and the middle a diamond. This applies to vessels engaged in replenishment at sea, which are restricted by the nature of the operation.