To how many degrees abaft the beam on the vessel’s side must a sidelight show?

To how many degrees abaft the beam on the vessel’s side must a sidelight show?

• A. 12.5 degrees
• B. 22.5 degrees
• C. 45 degrees
• D. 90 degrees

Answer: (B)

Sidelights are there to identify which side of the vessel you’re on, and they’re designed to be visible within a specific angular sector relative to the ship’s beam. The regulation specifies that a sidelight extends its visibility to a small amount abaft the beam on the vessel’s side, ensuring that other vessels approaching from the side can still see it without it being confused with a stern light. That’s why 22.5 degrees is the best answer. It matches the standard limit for how far behind the beam the sidelight remains visible on the side. The other numbers don’t fit that specific aft-limit requirement and would misstate how the sidelight’s visibility is restricted.

Sidelights are there to identify which side of the vessel you’re on, and they’re designed to be visible within a specific angular sector relative to the ship’s beam. The regulation specifies that a sidelight extends its visibility to a small amount abaft the beam on the vessel’s side, ensuring that other vessels approaching from the side can still see it without it being confused with a stern light.

That’s why 22.5 degrees is the best answer. It matches the standard limit for how far behind the beam the sidelight remains visible on the side. The other numbers don’t fit that specific aft-limit requirement and would misstate how the sidelight’s visibility is restricted.