To amend the requirements for the issuance and retention of licenses, certificates of registry and merchant mariners' documents; and for other purposes.

Amends Federal law to require that the Secretary of the department in which the Coast Guard is operating: (1) prior to issuing a merchant mariner's document or an endorsement to such a document, find that the applicant is qualified as to character and habits of life; and (2) determine the term of validity of a merchant mariner's document and of a certificate of registry. Allows documents and certificates to be renewed under regulations prescribed by the Secretary.

Adds habits of life to the qualifying criteria for issuance of merchant seamen certificates of registry as pursers, medical doctors, and professional nurses.

Amends provisions relating to licenses, certificates of registry, and merchant mariners' documents to allow suspension or revocation if the holder has been convicted within five years of: (1) driving under the influence of, or impaired by, alcohol or a controlled substance; or (2) a traffic violation arising in connection with a fatal traffic accident, reckless driving, or racing on the highways. Allows suspension or revocation, in addition, if the holder: (1) has had a license to drive denied, canceled, revoked, or suspended in any U.S. jurisdiction for cause; and (2) that cause would reflect adversely on the individual's fitness to serve.

Amends the Independent Safety Board Act of 1974 to remove from the list of duties of the Board that of reviewing on appeal the decisions of the Commandant of the Coast Guard related to revoking, suspending, or denying a license, certificate, document, or register in proceedings under specified provisions of Federal law.

Amends provisions of Federal law relating to manning of vessels to require the chief mate to temporarily relieve the individual in command if the chief mate and the next senior crewmember on board a vessel determine that reasonable cause exists to believe that the individual in command is intoxicated by dangerous drugs or alcohol and is therefore incapable of commanding the vessel. Requires the chief mate to log the details and report to the Secretary.