Question 35 GLI06 - Master or Mate of LT 100 GRT

The Correct Answer is A **Explanation for Option A (one prolonged blast):** Option A is correct because the U.S. Inland Rules of Navigation (specifically Rule 34(d)) require a power-driven vessel, when leaving a dock or berth, to sound **one prolonged blast** (a prolonged blast is defined as lasting 4 to 6 seconds). This signal serves as a warning to other vessels operating nearby that the vessel is underway and may be obstructing the fairway or channel. **Explanation for Incorrect Options:** * **B) four short blasts:** Four short blasts is the danger signal used to indicate that a vessel is in doubt about the intentions of an approaching vessel or believes a collision may occur. It is not the required signal for leaving a dock or berth. * **C) one long blast:** While the duration of a "prolonged blast" (4-6 seconds) is often colloquially referred to as "long," the official terminology in the Rules is "prolonged blast." More importantly, the signal "one prolonged blast" (A) is correct, whereas "one long blast" (C) is a non-standard or ambiguously defined term, making A the precise and correct regulatory answer. * **D) no signal is required:** This is incorrect. A clear warning signal is required by regulation when a vessel leaves a dock or berth and enters a channel or fairway, as this maneuver often involves restricted visibility and movement across traffic lanes.