Question 19 GLI04 - Mate of LT 500-1600 GRT

The Correct Answer is A. **Explanation of why option A is correct:** The fundamental rule for determining collision risk (under both International and Inland Rules of the Road, specifically Rule 7) is that risk exists if the Compass Bearing of an approaching vessel does not appreciably change (i.e., remains constant) and the distance (range) is decreasing. * **Bearing is constant:** This indicates that the vessel is approaching the point of interception on a straight relative course. * **Range is decreasing:** This means the vessel is getting closer. The combination of a constant bearing and decreasing range unequivocally satisfies the criteria for an existing risk of collision, regardless of the relative position (even if the vessel is coming from the quarter, though the rules generally apply most acutely to vessels ahead of the beam). **Explanation of why the other options are incorrect:** * **B) A vessel is 22 degrees abaft your port beam, range increasing, bearing is constant.** * **Range increasing:** If the vessel is moving further away, there is no risk of collision. The vessels are diverging, not converging. * **C) A vessel is broad on your starboard beam, range decreasing, bearing changing rapidly to the right.** * **Bearing changing rapidly:** A rapid change in bearing means the vessels are passing well clear of each other. The approaching vessel's relative motion is crossing your track line quickly, indicating that it will pass ahead or astern without converging on your position. * **D) A vessel is 22 degrees on your port bow, range increasing, bearing changing slightly to the right.** * **Range increasing:** As in option B, if the range is increasing, the vessels are diverging, and there is no risk of collision.