What does five or more short blasts from a boat mean?

Five or more short blasts from a boat typically signal danger or uncertainty about another vessel's intentions, particularly in situations where visibility is poor. This sound signal is used to communicate to nearby boats that the operator is unsure of their course and wants to alert them to the potential for collision. It is part of the sound signal regulations outlined in the International Regulations for Preventing Collisions at Sea (COLREGs).