46 U.S.C. § 7304
Section 7304 · Citizenship notation on merchant mariners documents
Amended 1 time on record
An individual applying for a merchant mariner's document shall provide satisfactory proof that the individual is a citizen of the United States before that notation is made on the document.
Editorial notes U.S. Code · Office of the Law Revision Counsel
Section 7304 specifies, that before a merchant mariner's document is noted to specify that the individual is a U.S. citizen, the individual must provide satisfactory proof that he is a citizen. This does not impose a requirement of United States citizenship as a condition for issuance of a document.