46 C.F.R. § 13.403 Eligibility: Experience.
Title 46 - Shipping
(a) Each applicant for a “Tankerman-Assistant” endorsement shall present— (1) Evidence of at least 90 days of deck service on tankships or self-propelled tank vessels certified to carry DL or LG appropriate to the endorsement applied for; or (2) A certificate of completion from a course in DL or LG appropriate for the endorsement applied for as prescribed in §13.409. (b) Each applicant already holding an MMD endorsed “Tankerman-Assistant” for DL and seeking one for LG, or the converse, shall— (1) Provide evidence of at least half the service required in paragraph (a)(1) of this section; or (2) Meet the requirement of a course in DL or LG appropriate for the endorsement applied for as prescribed in §13.409. [CGD 79–116, 60 FR 17142, Apr. 4, 1995, as amended by CGD 79–116, 62 FR 25134, May 8, 1997]
Title 46: Shipping
PART 13—CERTIFICATION OF TANKERMEN
Subpart D—Requirements for “Tankerman-Assistant” Endorsement
§ 13.403 Eligibility: Experience.

