What do eleven prolonged blasts mean on a boat?

Eleven prolonged blasts on a boat signal a warning to other vessels, indicating that the vessel is in distress or experiencing an emergency situation. This sound signal is part of the International Regulations for Preventing Collisions at Sea (COLREGs) and is used to alert nearby boats to the need for assistance. It’s crucial for maintaining safety on the water by ensuring that other vessels are aware of potential dangers.