Which document must be on board during inspections of commercially operated vessels?

The requirement for the vessel’s documentation or registration to be onboard during inspections of commercially operated vessels is rooted in maritime law and regulations. This document provides proof of the vessel’s ownership, compliance, and operational status, which is essential for the inspection process. It verifies that the vessel is legally registered and meets the standards set forth by the United States Coast Guard and other regulatory bodies.

Having this documentation available allows the inspecting officer to confirm the vessel’s identification, verify its registration details against the inspection records, and ensure compliance with safety and operational regulations. Without this documentation, it would be challenging to assess the legal status and safety compliance of the vessel, which is crucial for protecting both the crew and passengers.

In contrast, while personal identification of the captain, the passenger manifest, and a log of previous inspections may also be relevant for specific circumstances or types of inspections, they do not fulfill the primary legal requirement that directly pertains to the vessel's operational legitimacy during formal inspections.