While underway and in sight of another vessel a mile ahead, you put your engines on astern propulsion. Which statement concerning whistle signals is TRUE?

• A. You need not sound any whistle signals.
• B. You must sound one short blast
• C. You must sound three short blasts
• D. You must sound two long blasts

Answer: (A)

Whistle signals are used to communicate intentions to other vessels to avoid collision. Engine order changes and reversing are actions typically conveyed to your own engine room, not as mandatory whistle blasts to nearby vessels. Therefore, simply putting the propeller in astern propulsion does not require you to sound any whistle signals. If there were a real need to communicate a maneuver to the other vessel—such as altering course or stopping—proper whistle signals would be used for that situation, but reversing alone does not mandate one.