Question 16 ONC01 - Master/Chief Mate Unlimited Tonnage

The Correct Answer is C 1. **Why option C ("navigating in or near an area of restricted visibility") is correct:** The steering and sailing rules concerning vessels in restricted visibility are governed by Rule 19 of the COLREGs (International Regulations for Preventing Collisions at Sea). Rule 19 applies to vessels "not in sight of one another when navigating **in or near an area of restricted visibility**." This broad definition ensures that vessels take precautionary measures (such as reducing speed, maneuvering with caution, and sounding appropriate signals) before entering, while operating within, or when positioned just outside an area of fog, mist, falling snow, heavy rainstorms, or any other cause restricting visibility. The rules are preventative and require action as soon as the restricted visibility is identified, even if the vessel has not yet fully entered the affected zone. 2. **Why the other options are incorrect:** * **A) only if they have operational radar:** Radar is a valuable tool under Rule 19, and vessels equipped with it must use it properly. However, the requirement to follow the rules (reducing speed, sounding signals, etc.) applies to **all** vessels navigating in restricted visibility, regardless of whether they are equipped with or have operational radar. * **B) in sight of one another in fog:** If vessels are in sight of one another, they switch from the Restricted Visibility Rules (Rule 19) to the regular Steering and Sailing Rules (Rules 11 through 18), such as Head-on, Crossing, and Overtaking situations. Rule 19 specifically applies when vessels are **not** in sight of one another. * **D) only if they are showing special purpose lights:** Special purpose lights (such as lights for towing, fishing, dredging, etc.) indicate a vessel's status or limitations. While these lights are important, they are unrelated to the requirement to follow the rules concerning speed and maneuvering in restricted visibility (Rule 19). All vessels must comply with Rule 19, regardless of their operational status or the lights they are showing.