Section 138.410 - Conduct of external audits(a) External audits must be conducted by an auditor from a TPO and cover all elements of the TSMS requirements of this subchapter, but may be conducted on a sampling basis of each of those TSMS elements.(b) External audits must be of sufficient depth and breadth to ensure the owner or operating manager effectively implemented its TSMS throughout all levels of the organization, including onboard its vessels.(c) The auditor must be provided access to examine any requested documentation, question personnel, examine vessel equipment, witness system testing, and observe personnel training, including drills, as necessary to verify TSMS effectiveness.(d) The auditor may broaden the scope of the audit if:(1) The TSMS is incomplete or not effectively implemented;(2) Conditions found are not consistent with the records; or(3) Unsafe conditions are identified.(e) The auditor may verify compliance with vessel standards and TSMS requirements through a review of objective evidence such as checklists, invoices, and reports, and may conduct a visual sampling onboard the vessels to determine whether or not the conditions onboard the vessel are consistent with the records reviewed.(f) If an auditor identifies a major non-conformity during the course of the external audit, then the auditor must notify the local Officer in Charge, Marine Inspection (OCMI) within 24 hours and the owner or managing operator's designated representative in accordance with the TSMS applicable to the vessel.