Question 22 GLI08 - Limited OUPV

The Correct Answer is B **Explanation for B (Correct Option):** Option B is correct because it directly reflects the allowance stipulated in the International Regulations for Preventing Collisions at Sea (COLREGs), Rule 20(b). This rule states that a vessel may exhibit lights or shapes other than those prescribed by the Rules, provided that such lights or shapes **"do not impair the visibility or distinctive character of a light prescribed in these Rules, or interfere with the keeping of a proper look-out."** The primary concern for any additional light is safety, and anything that distracts the crew or hinders their ability to see required navigation lights (i.e., interferes with the look-out) is prohibited. **Explanation for A (Incorrect Option):** Option A ("have a lesser range than the prescribed lights") is incorrect. While additional lights should generally not overpower the prescribed lights, the Rules do not specify a maximum range or a requirement that they must have a range *less* than the navigation lights. The key requirement is that they must not impair the visibility of the prescribed lights (Rule 20(b)). An additional light having a greater range is acceptable as long as it does not interfere with the look-out or the clarity of the required lights. **Explanation for C (Incorrect Option):** Option C ("are not the color of either sidelight") is incorrect as a standalone requirement. Although an additional light must not impair the distinctive character of the prescribed lights (which includes color), the only prohibited colors for additional lights are green, red, and white lights that might be mistaken for required navigation lights (Rule 20(a)). However, the rules do not strictly forbid the *color* of a sidelight (red or green) from being used in an auxiliary light (like deck illumination), provided it clearly does not resemble a sidelight or interfere with the look-out. The key prohibition is interference (Option B), not merely color restriction. For example, a yellow or blue light is neither sidelight color but could still be prohibited if it interferes with the look-out. **Explanation for D (Incorrect Option):** Option D ("All of the above") is incorrect because both A and C are not accurate or complete descriptions of the requirements laid out in COLREGs for exhibiting non-prescribed lights. The sole necessary requirement encompassing all safety concerns is covered by Rule 20(b), accurately summarized in Option B.