46 C.F.R. § 12.905 – General requirements.

(a) Any seafarer may serve on a passenger vessel on an international voyage and perform duties that involve safety or care for passengers, only after—
1. (1) Meeting the appropriate requirements of the STCW Regulation V/2 and of section A-V/2 of the STCW Code (incorporated by reference, see § 12.103 of this part); and
2. (2) Holding documentary evidence to show that the mariner meets these requirements through approved or accepted training.
(b) Seafarers who are required to be trained in accordance with paragraph (a)(1) of this section must, at intervals not exceeding 5 years, provide evidence of maintaining the standard of competence.
(c) The Coast Guard will accept onboard training and experience, through evidence of 1 year of sea service within the last 5 years, as meeting the requirements of paragraph (a)(2) of this section.
(d) Personnel serving onboard small passenger vessels engaged in domestic, near-coastal voyages, as defined in § 15.105(g)(1) of this subchapter, are not subject to any obligation for the purpose of this STCW requirement.