What sound signal indicates that a vessel is at anchor?

Answer: C — One short blast followed by two long blasts

The sound signal that indicates a vessel is at anchor is made up of one short blast followed by two long blasts. This specific sequence is used as a warning to other vessels of the presence of an anchored vessel, helping to prevent collisions and maintain safety in navigable waters. A short blast, which lasts about one second, followed by two long blasts, each lasting about four to six seconds, effectively communicates that the vessel has dropped anchor. This signal is essential for informing nearby vessels of the anchored status, as it helps them to take necessary precautions to avoid the area. Other sound signals are designated for different circumstances. For instance, one short blast alone may indicate a change in course to starboard, while two short blasts signify a change in course to port. The three long blasts signal a vessel that is not under command or unable to maneuver. Understanding these specific sound signals is crucial for ensuring safe navigation and communication between vessels in various situations.