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

A prolonged blast, as defined in the COLREGs (International Regulations for Preventing Collisions at Sea), specifically refers to a sound signal made with a whistle or horn that lasts for a duration of four to six seconds. This duration is critical for ensuring that the signal is heard and understood by nearby vessels, particularly in situations where visibility is low or there is potential danger.

The use of a prolonged blast serves various purposes, such as warning other vessels of your presence or signaling distress. Understanding this specific duration helps mariners communicate effectively in marine environments, contributing to safety on the water. Thus, identifying the correct duration reinforces the importance of effective signaling in preventing collisions.