Question 304 Rules of the Road

The correct answer is D) The sounding of the danger signal is mandatory. According to the Inland Navigation Rules, Rule 34(d), when vessels are in doubt as to the other vessel's intentions, the vessel that is the stand-on vessel shall sound the danger signal, which is five or more short and rapid blasts of the whistle. This is a mandatory requirement to alert the other vessel of the potential danger and uncertainty. The other answer choices are incorrect because A) is for a different situation, B) is not the correct signal, and C) is incorrect as the sounding of the danger signal is required in this circumstance, not optional.