INLAND ONLY You are operating a vessel through a narrow channel and your vessel must stay within the channel to be navigated safely. Another vessel is crossing your course from starboard to port, and you are in doubt as to her intentions. Which of the following actions should you take?

Correct Answer: Option A — must sound the danger signal

Under Inland Rules 34(d) and Rule 9, when operating in a narrow channel where doubt exists regarding another vessel's intentions, mariners must immediately sound the danger signal consisting of at least five short and rapid blasts to warn approaching traffic of potential collision risks.