What does the blast mean in foggy conditions On a boat?

In foggy conditions, a blast refers to a sound signal made by a boat's horn or whistle to alert other vessels of its presence. This is crucial for safety, as visibility is limited, and the sound helps prevent collisions. The International Regulations for Preventing Collisions at Sea (COLREGs) specify the duration and frequency of these blasts to communicate a vessel's position and intentions effectively. Typically, a prolonged blast lasts about four to six seconds and is repeated at regular intervals.