Question 23 ONC04 - Mate of LT 500-1600 GRT

The Correct Answer is D **Explanation for Option D (Correct):** Option D ("if the bearing of an approaching vessel does not appreciably change") is the statement directly extracted from both the International Regulations for Preventing Collisions at Sea (COLREGs) and the corresponding Inland Rules. Rule 7 (Risk of Collision), paragraph (a)(i), states that one of the factors indicating risk of collision is if "the bearing of an approaching vessel does not appreciably change." This principle, known as Constant Bearing, Decreasing Range (CBDR), is the primary and definitive indicator specified in the Rules for when risk of collision shall be deemed to exist. **Explanation for Incorrect Options:** * **A) whenever a vessel crosses ahead of the intended track of another vessel:** While crossing situations are dangerous and require specific action (Rule 15), the act of crossing ahead does not automatically *deem* risk of collision to exist under the criteria of Rule 7. Risk exists when the bearing is constant or the range is decreasing significantly. * **B) if one vessel approaches another so as to be overtaking:** Overtaking situations (Rule 13) are defined by the angle of approach, but like crossing, the situation itself does not constitute the rule for *deeming* risk of collision. Risk must still be assessed based on bearing change and range, although Rule 13 makes it clear that the overtaken vessel is the stand-on vessel until finally past and clear. * **C) whenever two vessels approach from opposite directions:** Vessels approaching nearly end-on (Rule 14) is a specific type of situation that requires action, but Rule 7 explicitly states that risk of collision shall be deemed to exist *if* the bearing does not appreciably change, regardless of the angle of approach (end-on, crossing, or overtaking). Approaching from opposite directions is a dangerous scenario, but not the technical definition provided by the Rules for *deeming* risk to exist.