Question 572 Rules of the Road

The correct answer is D) 22.5° abaft the beam. The arc of visibility for sidelights on both international and inland vessels is from right ahead to 22.5° abaft the beam. This is specified in the navigation rules, which require sidelights to be visible from right ahead to 22.5° abaft the beam on the respective side of the vessel. The other options are incorrect because the arc of visibility does not extend to 135° abaft the beam (A), is not exactly abeam (B), and does not extend 22.5° forward of the beam (C).