When altering course to port, what sound signal should be used?

When altering course to port, the appropriate sound signal to use is two short blasts. This signal is a recognized means of communication between vessels, primarily to convey intentions on the water. It signifies that the vessel making the signal is changing its course to port (left side when facing forward).

The use of two short blasts is established by the International Regulations for Preventing Collisions at Sea (COLREGs) as a standardized method for vessels to communicate their actions in order to promote safety and avoid collisions. By signaling with two short blasts, other vessels are alerted to the change in direction, which allows for better situational awareness and coordination among operators.

Understanding this signaling is crucial for maintaining safe navigation, especially in congested or limited waters where clear communication can prevent misunderstandings and accidents.