BOTH INTERNATIONAL & INLAND Your vessel is underway in fog and you hear one prolonged and three short blasts. Which vessel would use this identity signal?

Correct Answer: Option A — A vessel being towed (manned)

Rule 35(c) dictates that a vessel being towed, or if more than one vessel is towed, the last vessel of the tow, if manned, shall sound one prolonged followed by three short blasts at intervals of not more than two minutes. This signal identifies the presence of the towed unit.