Question 35 ONC06 - Master LT 100 GRT

The Correct Answer is A **Explanation for Option A (one prolonged blast):** Option A is correct based on the Inland Navigation Rules, specifically Rule 34(d). This rule mandates that a power-driven vessel, when leaving a dock or berth, is required to sound **one prolonged blast** (a prolonged blast is defined as a blast of four to six seconds duration). This signal serves as a warning to other vessels in the immediate vicinity that the vessel is underway and leaving its fixed position. **Explanation for Incorrect Options:** * **Option B (four short blasts):** A signal of four short blasts is not a standard whistle signal for leaving a dock or berth. A specific combination of short blasts (e.g., five or more short and rapid blasts) is used as the danger or doubt signal (Rule 34(d)), and single short blasts are used for maneuvering signals (e.g., passing signals). * **Option C (one long blast):** While "prolonged blast" and "long blast" are sometimes used interchangeably in colloquial speech, the Navigation Rules strictly define the required signal as **one prolonged blast**. Using the specific terminology of "prolonged" is crucial, and "long" is not the designated term under Rule 34(d). * **Option D (no signal is required):** This is incorrect. The vessel is specifically required by Inland Rule 34(d) to sound the prolonged blast when leaving the dock or berth to notify other traffic.