Question 33 ONC07 - OUPV-Near Coastal

The Correct Answer is B **Explanation for Option B (67.5°):** Option B is correct because it aligns with the specifications set forth in the International Regulations for Preventing Collisions at Sea (COLREGs), Rule 21(b) (and the equivalent domestic inland regulations). A stern light must be positioned to show an unbroken light over an arc of the horizon of **135 degrees** (112.5° + 22.5° = 135°). This arc must be centered so that it shows from dead astern to **67.5 degrees** forward on each side of the stern (67.5° + 67.5° = 135°). **Explanation of Incorrect Options:** * **A) 22.5°:** This angle is the arc covered by the masthead light *forward* of the 112.5° arc, or it is half the angular distance covered by the sidelights beyond the bow (45 degrees / 2 = 22.5 degrees), but it is not the required arc for the stern light on each side. * **C) 112.5°:** This is the arc of the horizon covered by the sidelights (red or green) individually, starting from dead ahead, but it is not the arc for the stern light on one side. * **D) 135.0°:** This is the *total* arc covered by the stern light (from 67.5° on one side to 67.5° on the other side), not the measurement for a single side of the stern. The question asks for the degrees "on each side of the stern."