How long is a 'prolonged blast' typically transmitted?

How long is a 'prolonged blast' typically transmitted?

• A. Two to three seconds
• B. One to two seconds
• C. Seven to nine seconds
• D. Four to six seconds

Answer: (D)

In sound signaling, a prolonged blast is defined as lasting four to six seconds. This duration is longer than a short blast, making the signal clearly audible and unmistakable at distance, especially in reduced visibility or noisy conditions. The 4–6 second window provides a clear, standardized interval that distinguishes a deliberate, sustained signal from brief emissions, which helps other vessels correctly interpret the intent.

In sound signaling, a prolonged blast is defined as lasting four to six seconds. This duration is longer than a short blast, making the signal clearly audible and unmistakable at distance, especially in reduced visibility or noisy conditions. The 4–6 second window provides a clear, standardized interval that distinguishes a deliberate, sustained signal from brief emissions, which helps other vessels correctly interpret the intent.