Question 15 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is A ### Explanation for Option A (Correct) Option A ("Neither vessel is the stand-on vessel.") is correct because when vessels are crossing in restricted visibility (fog) and are **not in sight of one another**, the general rules governing "crossing situations" (COLREG Rule 17, Stand-on vessel) and "actions to avoid collision" (COLREG Rule 8) are superseded by the rules governing conduct in restricted visibility (COLREG Rule 19). COLREG Rule 19(d) states that if a vessel detects the presence of another vessel by radar alone (or by hearing a fog signal, as implied by the scenario) and determines that a close-quarters situation is developing or there is risk of collision, she shall take avoiding action. Crucially, **Rule 19 does not establish a stand-on/give-way relationship.** Both vessels are required to act prudently, often meaning reducing speed to bare steerageway (Rule 19(e)) or stopping, and navigating with extreme caution until the risk of collision is over. Since neither vessel is designated the "stand-on" vessel, both must be prepared to maneuver or stop. ### Why Other Options Are Incorrect **B) The vessel which hears the other vessel's fog signal first** This is incorrect. The sequence in which signals are heard has no bearing on establishing navigational rights or duties under the COLREGs, especially not in a crossing situation in fog. Both vessels are equally bound by Rule 19 regardless of who detected whom first. **C) The vessel which has the other on her own starboard side** This is incorrect. While this phrasing describes the *give-way* vessel in a normal crossing situation (COLREG Rule 15), Rule 15 and Rule 17 (which establishes the stand-on vessel as the one with the other to port) only apply when vessels are **in sight of one another**. Rule 19 (Restricted Visibility) overrides these visual rules. **D) The vessel which has the other on her own port side** This is incorrect. This phrasing describes the *stand-on* vessel in a normal crossing situation (COLREG Rule 17), but again, this rule is inapplicable because the vessels are **not in sight** and are operating under COLREG Rule 19.