According to the hierarchy, which vessel is at the highest position?

The highest position in the hierarchy of vessel types in the context of COLREGs is held by a vessel not under command. This classification is critical because a vessel not under command is unable to maneuver due to some exceptional circumstances, which may include a mechanical breakdown or other emergencies. According to the rules, vessels not under command must be given priority in right-of-way situations because they cannot adhere to typical navigation regulations and may pose a risk to themselves and others if they are not accommodated.

Other vessel types, such as fishing vessels, power vessels, and sailing vessels, have their own responsibilities and right-of-way considerations as per the COLREGs, but they are expected to operate normally and are required to avoid collisions. Therefore, while these vessels have particular scenarios where they may hold a right-of-way, none have the same level of priority or urgency as a vessel that is not under command, which must be avoided at all costs by other vessels. This understanding of the hierarchy is essential for safe navigation and compliance with maritime regulations.