What scenario indicates a risk of collision?

The scenario indicating a risk of collision is when an approaching vessel is on a collision course with no change in bearing. This situation is critical because it implies that both vessels are on a straight path towards each other and that neither vessel is altering its course or speed. If the bearing remains constant, it becomes evident that the vessels will intersect at some point, leading to the potential for a collision if no action is taken.

In navigation, it’s essential to be aware of other vessels' positions and movements to prevent mishaps on the water. Recognizing this particular situation allows boat operators to take appropriate evasive actions, such as changing course or speed, to avoid an accident.

The other scenarios do not indicate a risk of collision. A vessel at rest in a harbor poses no immediate threat since it is stationary. When vessels are moving in the same direction with a safe distance, there is typically no imminent risk of collision, as the separation between them negates the likelihood. Lastly, a tugboat pulling a disabled vessel does not inherently indicate a risk of collision unless the vessels are approaching other vessels or navigating in a confined area without proper spacing or communication.