What is the required whistle signal for a power-driven vessel leaving a dock or berth?

The required whistle signal for a power-driven vessel leaving a dock or berth is one prolonged blast. This signal is crucial for safety and communication on the water. A prolonged blast serves to alert other vessels and operators in the vicinity that the power-driven vessel is preparing to depart from its location. This ensures that nearby vessels are aware of the vessel's movement, reducing the risk of collisions and enhancing navigational safety. Proper sound signaling is an essential part of maritime rules and helps maintain an organized and safe operating environment.

In contrast, other signals serve different purposes. For instance, one short blast typically indicates a right turn, while two short blasts indicate a left turn. A long blast has its own designated purposes in specific navigational contexts. Understanding the significance of each signal is vital for any operator on the water, as it promotes safety and effective communication among various vessels.