What is the significance of Rule 27?

Rule 27 of the COLREGs is significant because it addresses the whistle signals that vessels must use to communicate their intentions and actions while navigating in close quarters. This rule is essential for maintaining situational awareness among vessels, ensuring they understand each other’s maneuvers, especially in situations where visibility may be limited or in congested waters.

The use of standardized whistle signals helps prevent misunderstandings that could lead to dangerous situations, facilitating safe passage and interactions between vessels. For instance, one prolonged blast can indicate that a vessel is altering its course to starboard, while two prolonged blasts indicate a course alteration to port. The clarity provided by these signals enhances navigational safety, which is the primary purpose of this rule.

The other options pertain to different aspects of maritime operations that are not covered by Rule 27. For example, crew numbers and safety equipment relate to vessel manning and safety standards, while operating speeds are addressed under different rules referring to safe speed and navigational conduct.