On Inland waters, a vessel leaving a dock must sound how many prolonged blasts?

When a vessel is leaving a dock on inland waters, the correct signaling practice is to sound one prolonged blast. This signal is used to indicate the vessel's intention to depart from a berth, which helps other vessels and operators in the vicinity understand the movement and intentions of the departing vessel.

In the context of navigation rules, especially under the Inland Navigation Rules, the use of sound signals is crucial for safety and preventing collisions. A single prolonged blast serves as a clear communication to other vessels that the departing vessel is maneuvering and might be in a position where it could affect the traffic around it.

Understanding this signaling procedure is essential for ensuring safe navigation in busy or narrow waterways where multiple vessels may be present, and helps reinforce the importance of communication on the water. This is a foundational aspect of maritime operations, particularly in scenarios where visual aids may be limited or when visibility is impaired.