Final answer:
In response to the five short blasts from the vessel on your starboard bow, you should recognize this as a signal of doubt or uncertainty regarding intentions and be prepared to slow down, communicate, and potentially alter course if necessary.
It is critical to ensure safety through clear communication and to take action rather than waiting for another signal.
Step-by-step explanation:
When approaching another vessel on the water, it is important to understand and correctly respond to sound signals. In the scenario where the other vessel at one mile distant and on your starboard bow sounds a whistle signal of five short blasts, this indicates uncertainty or doubt in the other vessel's intentions or actions.
The appropriate response to this signal is to interpret it as a warning that the other vessel does not understand your intentions and is unsure of whether you are taking appropriate action to avoid a collision.
Given this information and in adherence to maritime navigation rules, the correct course of action would be to first assess the situation, including the speed and course of both vessels, and then communicate clearly.
If it is safe to do so, slowing down, stopping, or altering course to starboard may be necessary actions taken to ensure the safety of both vessels. Typically, more information is needed to determine the best avoidance maneuver, but in all cases, safety and clear communication are the priorities.
There is no single correct answer without more context, but generally speaking, the most prudent action would be to appropriately signal, slow down, and be prepared to take evasive action if necessary (option C).
Repeat signals only if it's clear on your action and always keep monitoring the situation vigilantly. It is not advised to wait for another whistle signal from the other vessel without taking some sort of action yourself (option D).