Question 23 GLI04 - Mate of LT 500-1600 GRT

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 from Rule 7(d)(i) of both the International Regulations for Preventing Collisions at Sea (COLREGs) and the Inland Rules. Rule 7 specifically addresses the 'Risk of Collision' and states that such risk "shall be deemed to exist" if the compass bearing of an approaching vessel does not appreciably change (especially when approaching a vessel of large size or approaching at close range). This constant bearing, decreasing range (CBDR) principle is the primary operational test used by mariners to determine if they are on a collision course. **Explanation of Incorrect Options:** * **A) whenever a vessel crosses ahead of the intended track of another vessel:** While crossing ahead of another vessel's track is an action that requires careful assessment and often necessitates immediate action to avoid collision, the mere act of crossing the track itself is not the official *definition* given by the Rules for when the risk of collision *shall be deemed to exist*. Risk must be determined earlier, usually by observing the bearing change. * **B) if one vessel approaches another so as to be overtaking:** Overtaking is a specific defined situation (Rule 13), but the risk of collision is generally assumed to be a possibility from the moment the overtaking vessel begins to approach. The Rule states that risk is deemed to exist based on bearing change, not merely based on the geometry of the encounter (overtaking). Furthermore, in an overtaking situation, the overtaken vessel is required to maintain course and speed, and the risk is primarily on the overtaking vessel to keep clear. * **C) whenever two vessels approach from opposite directions:** Vessels approaching from opposite directions are in a head-on situation (Rule 14), which is a defined meeting scenario. However, risk of collision *shall be deemed to exist* if the bearing remains constant (D), not merely because they are approaching one another. For example, two vessels might be approaching on opposite tracks but be safely offset (i.e., not CBDR) and therefore not be in immediate danger of collision.