Which whistle signal is used to stop tow operations?

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

Answer: (A)

In tow operations, sound signals are used to coordinate actions between the tug and the tow. A single prolonged blast is the standard, unambiguous signal to stop towing. It stands out over engine noise and distance and clearly communicates that the tow should cease and the line be taken in. Short blasts, by contrast, are used for other maneuvering or passing signals and don’t convey the explicit instruction to stop towing. So the one long blast is the best way to indicate stopping tow operations.