What type of document can a crewmember hold instead of a passport?

A seaman's book is recognized as a legitimate travel document for crewmembers, particularly those working on commercial ships. It serves as an identification document and record of employment and is specifically designed for individuals who are employed in the maritime industry. This document not only provides the holder with proof of their status as a crew member but also grants them certain travel rights, enabling them to board vessels and sometimes facilitating their entry into different countries without the need for a traditional passport.

In contrast, while a national ID might be useful for domestic situations or some regional travel, it typically does not meet the international standards required for seafaring duties. A visa card refers to a credit card and is not a travel document, and travel insurance does not serve as an identification document either. Therefore, the seaman's book stands out as the appropriate alternative to a passport for crewmembers.