While underway and in sight of another vessel more than 0.5 miles away, you reverse engines to full astern. Which whistle signal is TRUE?

While underway and in sight of another vessel more than 0.5 miles away, you reverse engines to full astern. Which whistle signal is TRUE?

• A. One long blast
• B. Three long blasts
• C. Five short blasts
• D. Three short blasts

Answer: (D)

Sound signals communicate your propulsion actions to nearby vessels so they can anticipate your maneuver. When you are underway and you reverse engines to full astern, you convey that specific action with three short blasts. This tells others that you are backing down, which helps prevent misinterpretation in a busy or changing situation. The other options don’t match this particular maneuver—each of those signals corresponds to different communications, not to backing down.

Sound signals communicate your propulsion actions to nearby vessels so they can anticipate your maneuver. When you are underway and you reverse engines to full astern, you convey that specific action with three short blasts. This tells others that you are backing down, which helps prevent misinterpretation in a busy or changing situation. The other options don’t match this particular maneuver—each of those signals corresponds to different communications, not to backing down.