What is a consequence for a vessel constrained by her draught according to Rule 18d?

A vessel constrained by her draught is one that is limited in its ability to navigate due to its deep draft, especially in shallow waters. According to Rule 18(d) of the COLREGs, vessels in this category are obligated to avoid impeding the safe passage of other vessels that can navigate safely in the prevailing conditions. This means that while they may have certain navigational challenges, their responsibility is to ensure that they do not hinder the movement of other vessels that are capable of navigating without such limitations.

This rule acknowledges the unique navigation issues faced by vessels constrained by their draught, but it also emphasizes the importance of maintaining safe navigation for all vessels involved. As a result, it underscores the responsibility of such vessels to be aware of and considerate towards other vessels in their vicinity.

Navigating aggressively, having no obligations, or ignoring navigational signals would contradict the fundamental principles of maritime safety and the obligations imposed by COLREGs on all vessels, regardless of their constraints. Therefore, the chosen answer accurately reflects the obligations imposed on vessels with a significant draught, reinforcing the need for safety and awareness in maritime navigation.