BOTH INTERNATIONAL & INLAND You see a vessel displaying the day signal shown in illustration D006RR below. The vessel may be which of the following?

Correct Answer: Option D — laying submarine cable

Rule 27(b) requires a vessel restricted in her ability to maneuver to display three shapes in a vertical line: a ball, a diamond, and a ball. This signal is used by vessels engaged in operations such as laying or picking up a submarine cable, which limits their ability to maneuver.