What does Rule 18 specify regarding vessel obligations?

Answer: B — It details obligations for vessels constrained by their draft and fishing vessels

Rule 18 of the COLREGs specifically addresses the responsibilities of certain types of vessels when they are navigating in relation to one another. It outlines the obligations of vessels such as those constrained by their draft, vessels engaged in fishing, vessels not under command, and vessels restricted in their ability to maneuver. This rule aims to prevent collisions by establishing clear norms for which vessels must give way to others under various circumstances. The choice indicating that Rule 18 details obligations for vessels constrained by their draft and fishing vessels accurately captures its content, emphasizing the distinction between different types of vessels and their respective navigation responsibilities. This specificity is crucial for safe navigation practices among vessels of differing capabilities and operational limitations.