What is the duration of a prolonged blast as defined in the regulations?

The duration of a prolonged blast is defined in the regulations as lasting from four to six seconds. This specification is part of the International Regulations for Preventing Collisions at Sea (COLREGs), which outline the correct use of sound signals to communicate intentions and ensure safety at sea. A prolonged blast serves as a distress signal or indicates that a vessel is navigating in limited visibility, such as fog or heavy rain.

The four to six seconds duration allows a clear and recognizable sound that can be distinguishable by other vessels, reducing the risk of misunderstanding and aiding in the reliable communication of one’s presence on the water. This standardization is essential for maintaining safety and preventing collisions, especially in conditions where visibility is compromised.

In contrast, the other options do not meet the regulatory requirements for a prolonged blast. They either fall short of the minimum duration or extend beyond the defined parameters, which could lead to confusion or misinterpretation, thus undermining the critical role of sound signals in maritime navigation safety.