What is the primary concern of Rule 15?

Rule 15 addresses head-on situations, highlighting the protocol for vessels that are approaching each other directly. In these scenarios, both vessels are typically to maintain their courses and speeds, as well as take necessary actions to avoid collisions by altering their course to starboard, resulting in passing on the port side of each vessel.

Understanding this rule is crucial for safe navigation, as it helps prevent misunderstandings during encounters between vessels on a collision course. By designating how vessels should behave in such situations, Rule 15 plays a key role in promoting safety at sea, ensuring that all mariners are aware of their responsibilities when they encounter another vessel head-on.

The other options revolve around different aspects of maritime rules, but the primary focus of Rule 15 is specifically on head-on encounters, outlining the expectations for the vessels involved.