46 CFR § 13.303 - Service requirements.
Each applicant for a tankerman-PIC (barge) endorsement for DL or LG must meet the requirements of either paragraphs (a) and (b) or paragraph (c) of this section.
(a) Each applicant must present evidence of—
(1) At least 60 days of service, whether by shore-based or by vessel-based personnel, on one or more tank vessels certified to carry DL or LG appropriate to the endorsement applied for; or
(2) At least 6 months of closely related service directly involved with tank barges appropriate to the endorsement applied for; and
(b) Participation, under the supervision of a tankerman-PIC or tankerman-PIC (barge), in at least 10 transfers of liquid cargo in bulk of the classification desired on any tank vessel, including at least—
(1) Five loadings and five discharges;
(2) Two commencements of loading and two completions of loading; and
(3) Two commencements of discharge and two completions of discharge.
(c) Each applicant already holding an MMD or MMC endorsed tankerman-PIC (barge) for DL and seeking an endorsement for LG, or the converse, must—
(1) Provide evidence of at least half the service required by paragraph (a) of this section; and
(2) Comply with paragraph (b) of this section, except that he or she need provide evidence of only three loadings and three discharges along with evidence of compliance with paragraphs (b)(2) and (3) of this section.