Question 23 ONC05 - Master or Mate of LT 200 GRT

The Correct Answer is D The statement regarding when risk of collision shall be deemed to exist is defined explicitly in Rule 7 (Risk of Collision) of both the International Regulations for Preventing Collisions at Sea (COLREGs) and the Inland Rules. **Why Option D is Correct:** Option D, "if the bearing of an approaching vessel does not appreciably change," is the primary and definitive criterion stated in Rule 7(a)(i). This phenomenon—where the compass bearing (relative position) of another vessel remains relatively constant while the distance decreases—means that the vessels are on a collision course. This is often referred to as Constant Bearing, Decreasing Range (CBDR). Therefore, the Rules state that this situation immediately deems a risk of collision to exist. **Why the Other Options are Incorrect:** * **A) whenever a vessel crosses ahead of the intended track of another vessel:** While crossing situations often involve risk, the mere act of crossing a projected track does not automatically deem risk of collision to exist under the criteria of Rule 7. A vessel might cross well ahead at a safe distance and speed, or the bearing may change significantly, indicating no collision risk. * **B) if one vessel approaches another so as to be overtaking:** Rule 13 (Overtaking) defines an overtaking situation, and Rule 14 (Head-on) and Rule 15 (Crossing) define other situations. While these situations *may* involve risk (and require specific action), the defining factor for the *existence* of risk is not the type of encounter (like overtaking) but the bearing change criterion established in Rule 7. * **C) whenever two vessels approach from opposite directions:** This describes a head-on situation (Rule 14). While a head-on approach certainly necessitates early action and involves risk, risk of collision is *deemed* to exist based on the constant bearing rule (D), not merely because two vessels are approaching from opposite directions (they might pass safely at a great distance).