Question 16 ONC03 - Master LT 500-1600 GRT

The Correct Answer is C 1. **Why option C ("navigating in or near an area of restricted visibility") is correct:** The International Regulations for Preventing Collisions at Sea (COLREGs), Rule 19 (Conduct of Vessels in Restricted Visibility), states that this rule applies to vessels **"when navigating in or near an area of restricted visibility."** This scope is intentionally broad, covering both vessels actively experiencing reduced visibility (like fog, heavy rain, or snow) and vessels approaching such areas, ensuring they take precautions before the actual restriction impacts them. The rules apply universally to all vessels, whether they are international (high seas) or inland waters (where COLREGs or compatible local rules are enforced). 2. **Why option A ("only if they have operational radar") is incorrect:** While radar is a critical tool mentioned specifically in Rule 19 for determining risk of collision and taking appropriate action, the entire set of restricted visibility rules (including obligations regarding speed, listening, and sound signals) applies to **all** vessels, regardless of whether they are equipped with or have operational radar. 3. **Why option B ("in sight of one another in fog") is incorrect:** If vessels are **in sight** of one another, they switch to the corresponding applicable Rules (e.g., Rule 14, Head-on Situation; Rule 15, Crossing Situation; Rule 17, Action by Stand-on Vessel), which govern vessels when they are in sight. Rule 19 specifically applies when vessels **are not** in sight of one another. 4. **Why option D ("only if they are showing special purpose lights") is incorrect:** Rule 19 applies to **all** vessels navigating in or near restricted visibility. Special purpose lights (such as those for vessels constrained by their draft, fishing vessels, or vessels not under command) are used to indicate a vessel's status, but the requirement to follow the rules for restricted visibility is mandatory for every vessel, regardless of its operational status or the lights it is showing.