BOTH INTERNATIONAL & INLAND You see a vessel's green sidelight bearing due east from you. Which direction may the vessel be heading?

Correct Answer: Option D — southwest (225°)

Sidelights cover an arc of 112.5 degrees. If you observe a green light bearing due east (090°), the vessel is showing its starboard side. To be visible, the vessel must be heading in a direction that places your position within its starboard sector, which is 225° (southwest).