While underway and in sight of another vessel a mile ahead you put your engines on astern propulsion. Which statement concerning whistle signals is TRUE?

When a vessel is underway and in sight of another vessel, the Rules of the Road stipulate certain requirements for whistle signals to communicate intentions. In this scenario, when you put your engines in astern propulsion, it is critical to note that the appropriate action is to signal your intentions to the other vessel.

The correct understanding here is that if you are simply backing your vessel while in sight of another and there is no further maneuvering that could create a risk of collision or necessitate further signaling, you are not required to sound any whistle signals. This is because the act of going astern does not inherently mandate a specific sound signal unless it is being done as part of a manoeuvre that would impact the safe passage of the other vessel.

In contrast, certain options involve sounding specific signals which are typically reserved for particular circumstances, such as when you are overtaking or when you are making a specific maneuver that requires greater communication. However, in the context of simply engaging astern propulsion where no immediate danger or maneuver is present, those signaling requirements do not apply. This illustrates the importance of using whistle signals only when necessary based on the navigational situation.