Question 19

The Correct Answer is A. **Explanation of why option A is correct:** The risk of collision exists if the **Compass Bearing** of an approaching vessel **does not appreciably change** (i.e., remains constant) and the **Range** (distance) is **decreasing**. This is the fundamental definition of a collision risk under the International Regulations for Preventing Collisions at Sea (COLREGs), Rule 7(a)(i). Option A describes a situation where the vessel is approaching ("range decreasing") and maintaining a constant bearing ("bearing is constant"). Although the vessel is starting from the quarter, if the bearing remains constant while the range decreases, the two vessels are on a collision course. **Explanation of why the other options are incorrect:** * **B) A vessel is 22 degrees abaft your port beam, range increasing, bearing is constant.** * While the bearing is constant, the range is **increasing**. If the range is increasing, the vessels are moving away from each other, and there is no risk of collision. * **C) A vessel is broad on your starboard beam, range decreasing, bearing changing rapidly to the right.** * Although the range is decreasing, the **bearing is changing rapidly**. A rapid or appreciable change in bearing indicates that the vessels will pass clear of each other, meaning no risk of collision exists, provided the vessels maintain course and speed. * **D) A vessel is 22 degrees on your port bow, range increasing, bearing changing slightly to the right.** * The range is **increasing**, meaning the vessels are moving away from each other. Even though the bearing is changing only slightly, the increasing range definitively rules out a risk of collision.