Sb-28 a collision could occur when the distance decreases and the bearing between two vessels changes.
The Correct Answer and Explanation is:
Correct Answer: True
A collision could occur when the distance between two vessels decreases and the bearing between them changes. This situation typically indicates that the two vessels are on converging courses, rather than on a constant bearing which might otherwise suggest a direct collision course.
Explanation
In maritime navigation, understanding relative motion between vessels is crucial to avoiding collisions. Two key indicators are used to assess collision risk: relative bearing and distance.
- Bearing Changes:
When one vessel observes another and notes that the bearing (the direction to the other vessel relative to one’s own heading) is changing, it means the two vessels are not on a straight line of approach. A constant bearing, on the other hand, with decreasing distance, is a classical indicator of a potential collision. However, even if the bearing is not constant, a collision is still possible if both vessels are maneuvering or are on intersecting courses. - Decreasing Distance:
A reduction in the range between two vessels suggests that they are closing in on each other. This alone doesn’t necessarily mean a collision will occur, but when combined with a changing bearing, it implies a crossing or converging situation where one vessel may be moving toward the other’s track. This could lead to a collision if appropriate avoiding action is not taken. - Rule of Good Seamanship and COLREGs:
According to the International Regulations for Preventing Collisions at Sea (COLREGs), all navigators must use all available means, including visual observation, radar, and AIS, to assess risk of collision and act early and decisively. A bearing change with decreasing distance is a clear signal that close monitoring and potential action are needed.
In conclusion, even though a constant bearing is a strong indication of a collision course, a changing bearing with decreasing distance can also be dangerous, particularly in complex or dynamic traffic scenarios. Therefore, the statement is true: a collision could occur under these circumstances.
