Question 23

The Correct Answer is D **Explanation for Option D (Correct Answer):** Option D, "if the bearing of an approaching vessel does not appreciably change," is the direct definition provided by Rule 7(d)(i) of the International Regulations for Preventing Collisions at Sea (COLREGs), which applies to both international and inland waters. This is the primary and most important criterion used to determine if a risk of collision exists. If the Compass Bearing (CB) to the approaching vessel remains constant, it means the vessels are on a collision course, regardless of the vessel's apparent motion or range. **Explanation for Incorrect Options:** * **A) whenever a vessel crosses ahead of the intended track of another vessel:** While crossing situations often involve risk, simply crossing ahead of an intended track is not the definitive rule for deeming risk of collision to exist. A vessel crossing far ahead and maintaining a changing bearing presents no risk of collision. The bearing change is the critical factor. * **B) if one vessel approaches another so as to be overtaking:** Overtaking situations (Rule 13) are defined by the approach angle, but the Rules state that risk shall be deemed to exist primarily when the bearing is constant (Rule 7). An overtaking vessel may be approaching on a course that will result in a clear miss (i.e., the bearing changes quickly), meaning no risk of collision exists under Rule 7(d). * **C) whenever two vessels approach from opposite directions:** Vessels approaching from opposite directions (head-on situations, Rule 14) certainly carry a high risk, but the definition in Rule 7 is based on the constant bearing. If two vessels approaching from opposite directions have courses that will result in a wide pass (i.e., a rapid change in bearing), the risk of collision, according to the rule, does not exist.