BOTH INTERNATIONAL & INLAND Which shapes shall a vessel servicing a pipeline during the day display?

Correct Answer: Option C — three black shapes in a vertical line; the highest and lowest are balls, and the middle one is a diamond

Rule 27(b)(iii) applies to vessels restricted in their ability to maneuver, including those servicing pipelines. The required day shapes are three shapes in a vertical line: the highest and lowest are balls, and the middle is a diamond. This signal alerts other vessels to the restricted nature of the operation.