46 C.F.R. § 13.120 Renewal of endorsement.
Title 46 - Shipping
An applicant wishing to renew a tankerman's endorsement shall meet the requirements of §12.02–27 of this chapter for renewing an MMD and prove either participation in at least two transfers within the last 5 years in accordance with §13.127(b) or completion of an approved course as described in §10.304. [CGD 79–116, 62 FR 25130, May 8, 1997]
Title 46: Shipping
PART 13—CERTIFICATION OF TANKERMEN
Subpart A—General
§ 13.120 Renewal of endorsement.

