Which of the following can establish a valid claim of nationality for a vessel?

A valid claim of nationality for a vessel can be established through several means, and it is important to understand each method's significance.

Documents proving ownership serve as a formal record that identifies the owner of the vessel, which is essential for determining nationality as many countries issue registration certificates that indicate a vessel's nationality based on ownership.

Flying a state flag is a prominent indicator of a vessel's nationality. By displaying a flag, the vessel is recognized as being registered with that particular state, and it is a visual representation of the vessel's citizenship in international waters.

Additionally, a verbal claim by the vessel's master can sometimes be considered when assessing nationality, especially in situations where formal documentation is lacking or not immediately available. The master's assertion, typically verified against records, can be used to support the claim of nationality.

All these elements combine to create a comprehensive understanding of a vessel's nationality, which is crucial for various legal jurisdictions, operational rules, and responsibilities on the high seas. Hence, all the listed methods contribute to establishing a valid claim of nationality for a vessel.