Question 3 RVR05 - Master of LT 100 GRT

The Correct Answer is B **Explanation of why option B ("it is a large course change") is correct:** This question relates to the International Regulations for Preventing Collisions at Sea (COLREGs), specifically Rule 8 (Action to Avoid Collision) and Rule 19(d) (Conduct of vessels in restricted visibility). The principle is consistent across both Inland and International rules derived from COLREGs. Rule 8(b) states: "Any alteration of course and/or speed to avoid collision shall, if the circumstances of the case admit, be **large enough to be readily apparent to another vessel observing visually or by radar**; a succession of small alterations of course and/or speed should be avoided." A large, readily apparent course change is crucial because: 1. **Clarity and Intent:** It immediately signals the vessel's intention to the other vessel involved, allowing them to confirm the avoidance maneuver and take appropriate action (or confirm that they have been seen and their movement is understood). 2. **Detection:** Small changes (often less than 5 degrees) are difficult to detect visually or on radar, especially if the other vessel is also moving or if radar plotting is inexact. Small changes often lead to doubt, delayed action, and potentially a closer quarters situation. Therefore, for a course change alone to be the most effective avoidance action, it must be large and unambiguous. *** **Explanation of why the other options are incorrect:** * **A) the course change is to starboard:** While COLREGs often mandate a starboard course change in specific meeting or crossing situations (Rules 13, 14, 15), Rule 8 refers to *any* avoidance action. The effectiveness of the action hinges on its magnitude (being readily apparent), not necessarily its direction, unless dictated by a specific rule applicable to the geometry of the encounter. * **C) it is done in a succession of small course changes:** This is directly contrary to Rule 8(b), which explicitly advises that "a succession of small alterations of course and/or speed should be avoided." Small, successive changes fail to signal intent clearly and are difficult to detect. * **D) it is NOT done too early:** Although timely action is essential (Rule 8(a) requires action to be taken "in ample time"), the effectiveness and clarity of the action itself are governed by Rule 8(b). Taking a large action early is usually the best practice. Taking a large action too late is ineffective, but the *characteristic* that makes the action effective when it is taken is its magnitude, not the timing relative to "too early" (which is subjective).