Question 35

The Correct Answer is A **Why Option A ("one prolonged blast") is correct:** The Inland Navigational Rules (specifically Rule 34(d)) govern whistle signals in U.S. inland waters. This rule states that a power-driven vessel leaving a dock or berth must sound **one prolonged blast** (a prolonged blast is defined as lasting from four to six seconds). This signal serves as a warning to any approaching vessels that the vessel is underway and leaving a restricted area, allowing other traffic to take appropriate action. **Why the other options are incorrect:** * **B) four short blasts:** A sequence of four short blasts is not a recognized standalone signal for leaving a dock or berth under the Inland Rules. A signal of at least five short and rapid blasts is the danger or doubt signal. * **C) one long blast:** While the term "long blast" is sometimes used colloquially, the official terminology in the Rules is "prolonged blast" (4–6 seconds). Using "long blast" as a distinct option from "prolonged blast" (A) suggests a difference in duration or intent, making the precise regulatory term (prolonged) the correct choice. * **D) no signal is required:** A signal is required under the Inland Rules to warn traffic that the vessel is maneuvering out of a restricted area (dock/berth) and entering the navigable channel. Therefore, silence is not permitted.