46 CFR § 13.119
Expiration of endorsement
April 15, 2021
An endorsement as tankerman is valid for the duration of the merchant mariner's document or merchant mariner credential on which the endorsement appears.
[CGD 79-116, 60 FR 17142, Apr. 4, 1995, as amended by USCG-2006-24371, 74 FR 11259, Mar. 16, 2009]