46 CFR § 138.310 - Internal audits for a TSMS certificate.
(a) Internal management audits must be conducted annually, within 3 months of the anniversary date of the TSMS certificate, to ensure the owner or managing operator is effectively implementing all elements of their TSMS.
(b) The internal management audit must ensure that management has implemented the TSMS throughout all levels of the organization, including audits of all the owner or managing operator's towing vessels to which a TSMS applies to ensure implementation at the operational level.
(c) The results of internal audits must be documented and maintained for a period of 5 years and made available to the Coast Guard upon request.
(d) Internal auditors:
(1) Must have knowledge of the management, its SMS, and the standards contained in this subchapter;
(2) Must have completed an ANSI/ISO/ASQ Q9001-2000 or ISO 9001:2008(E) (incorporated by reference, see § 136.112 of this subchapter) internal auditor/assessor course or Coast Guard-recognized equivalent;
(3) May not be the designated person, or any other person, within the organization that is responsible for development or implementation of the TSMS; and
(4) Must be independent of the procedures being audited, unless this is impracticable due to the size and the nature of the organization.