INTERNATIONAL ONLY In a narrow channel, a vessel trying to overtake another on the other vessel's port side, would sound a whistle signal of __________.

Correct Answer: Option B — two prolonged blasts followed by two short blasts

COLREG Rule 34(c)(i) dictates that an overtaking vessel operating within a narrow channel or fairway and intending to pass along the port side of the vessel ahead must sound two prolonged blasts followed by two short blasts.