Question 23

The Correct Answer is D **Explanation for D (Correct Answer):** Option D, "if the bearing of an approaching vessel does not appreciably change," is the direct quote (or definitive summary) from Rule 7(b) of the International Regulations for Preventing Collisions at Sea (COLREGs), which applies to both international (high seas) and inland (certain specified waters) scenarios. Rule 7 specifically dictates how the risk of collision is to be determined. Rule 7(b) states: "Such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change." This principle is fundamental to navigation because if the bearing remains constant, it indicates that the two vessels are on a collision course, regardless of their relative speed or size. **Why other options are incorrect:** * **A) whenever a vessel crosses ahead of the intended track of another vessel:** This describes a potentially close-quarters situation (often crossing scenarios), but crossing tracks alone does not automatically mean a risk of collision exists. The vessels might still pass safely with no risk, especially if the distance is great or they are moving slowly. Risk is determined by the change in bearing, not merely the crossing of tracks. * **B) if one vessel approaches another so as to be overtaking:** An overtaking situation is defined by Rule 13, and while it creates a duty for the overtaking vessel to keep clear, the risk of collision (the threshold determination) is still assessed using Rule 7. The vessels may be far apart, or the overtaking vessel may be safely altering course. Overtaking defines the relationship, not the specific moment risk is deemed to exist. * **C) whenever two vessels approach from opposite directions:** Vessels approaching from opposite directions describes a head-on scenario (Rule 14), which is a specific type of encounter requiring action. However, just like options A and B, approaching from opposite directions does not inherently mean risk of collision exists if the distance is very large or if they are slightly offset and the bearing is changing rapidly (indicating they will pass safely). The key test for deeming risk remains the constant bearing principle (Rule 7(b)).