🔍 Key Concepts

• Stern light arc of visibility and what direction it shines • Sidelights arcs of visibility and when you can/cannot see them • Definition of an overtaking situation (coming from more than 22.5° abaft the beam)

💭 Think About

• If you are approaching from astern, are you within the sector where the other vessel’s sidelights are visible, or mostly in the sector covered by the stern light? • Think about which lights are intended to tell other vessels you are behind them versus on their side or ahead. • In an overtaking situation at night, which navigation light specifically helps you identify that you are overtaking rather than crossing or meeting head‑on?

✅ Before You Answer

• Verify the arcs of visibility for sidelights (from right ahead to 22.5° abaft the beam). • Verify the arc of visibility for the stern light (135° centered on the stern). • Confirm that in a true overtaking situation, you are more than 22.5° abaft the beam of the vessel you are approaching.