46 CFR § 11.491
National officer endorsements for service on offshore supply vessels
April 15, 2021
(a) Each officer endorsement for service on offshore supply vessels (OSVs) authorizes service on OSVs as defined in 46 U.S.C. 2101(19) and as interpreted under 46 U.S.C. 14104(b), subject to any restrictions placed on the license or MMC.
(b) For those officers who previously received a 500 GRT limitation on their national officer endorsement due to the definition of OSV existing before October 15, 2010, the limitation will be raised to 1,600 GRT to be consistent with other national officer endorsements.