When passing another ship and rendering honors, how many signal blasts are used to call 'attention to port'?

To call 'attention to port' when passing another ship and rendering honors, two signal blasts are used. This practice is part of the protocol for demonstrating respect and recognition between vessels at sea, particularly in naval operations. When a ship wishes to draw attention to its port side, two short sound signals, typically made by a whistle or horn, are used to clearly communicate this intention to the passing vessel. Properly signaling helps maintain order and ensures that both vessels are aware of each other's presence and maneuvers, which is crucial for safety and adherence to maritime customs.