Question 44
GLI04BOTH INTERNATIONAL & INLAND Two power-driven vessels are crossing as shown in illustration D042RR below. Vessel "A" sounds three short blasts on the whistle. What is the meaning of this signal?

AI Explanation
The Correct Answer is D
**Explanation for Option D (Correct):**
The meaning of whistle signals is defined by the International Regulations for Preventing Collisions at Sea (COLREGs), which apply to both International and Inland waters (though specific inland rules may have slight variations, the basic maneuvering signals are consistent). Rule 34(a) governs maneuvering and warning signals. The signal of **three short blasts** means: **"I am operating astern propulsion"** (backing engines). This indicates that the vessel is actively using its engine to move backward or stop its forward motion.
**Explanation for Other Options (Incorrect):**
* **A) Vessel "A" intends to hold course and speed:** This is incorrect. A single short blast (one second) typically indicates an intention to alter course to starboard (when meeting or overtaking) or a general intent to maneuver, but there is no specific signal defined solely for "holding course and speed." "Holding course and speed" is the duty of the stand-on vessel, not a whistle signal.
* **B) Vessel "A" is sounding a signal of doubt:** This is incorrect. The signal of doubt or uncertainty (often called the "danger signal") is **five or more short and rapid blasts**.
* **C) Vessel "A" proposes to cross ahead of the other vessel:** This is incorrect. Intentions regarding crossing ahead are usually communicated through agreement (passing port-to-port or starboard-to-starboard, using one or two short blasts respectively) or determined by the rules of the road (give-way/stand-on). Three short blasts specifically signifies astern propulsion, not an intention to cross ahead.
Related Questions
#43 What is the color of the signal flare sent up by a submarine indicating that a torpedo has been fired in a
training exercise?#43 You are steering 257°T, and a light is picked up dead ahead at a distance of 13.3 miles at 2016. You change
course to pass the light 4 miles off abeam to starboard. If you are making 18.5 knots, what is your ETA at the
position 4 miles off the light?