46 CFR 11.491: Officer endorsements for offshore supply vessel service

Last reviewed: October 14, 2026

This section covers national officer endorsements for service on offshore supply vessels (OSVs). Such an endorsement authorizes service on OSVs, subject to any restrictions on the MMC. Older 500 GRT limitations will be raised to 1,600 GRT.

Applies toOfficers holding national officer endorsements for service on offshore supply vessels (OSVs).

What it says

  1. Each officer endorsement for service on OSVs authorizes service on OSVs as defined in 46 U.S.C. 2101 and as interpreted under 46 U.S.C. 14104(b).

    46 CFR 11.491(a)“authorizes service on OSVs as defined in 46 U.S.C. 2101 and as interpreted under 46 U.S.C. 14104(b)”

  2. The authorization to serve on OSVs is subject to any restrictions placed on the MMC.

    46 CFR 11.491(a)“subject to any restrictions placed on the MMC”

  3. For officers who previously received a 500 GRT limitation because of the OSV definition existing before October 15, 2010, the limitation will be raised to 1,600 GRT to be consistent with other national officer endorsements.

    46 CFR 11.491(b)“the limitation will be raised to 1,600 GRT to be consistent with other national officer endorsements”

Common questions

What does an OSV officer endorsement authorize?

It authorizes service on OSVs as defined in 46 U.S.C. 2101 and as interpreted under 46 U.S.C. 14104(b). Any restrictions placed on the MMC still apply.

“authorizes service on OSVs as defined in 46 U.S.C. 2101 and as interpreted under 46 U.S.C. 14104(b), subject to any restrictions placed on the MMC”

What happens to an older 500 GRT limitation on an OSV endorsement?

For officers who got the 500 GRT limitation because of the OSV definition before October 15, 2010, the limitation will be raised to 1,600 GRT.

“500 GRT limitation on their national officer endorsement due to the definition of OSV existing before October 15, 2010”

The text of 46 CFR 11.491

Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR

National officer endorsements for service on offshore supply vessels

(a) Each officer endorsement for service on offshore supply vessels (OSVs) authorizes service on OSVs as defined in 46 U.S.C. 2101 and as interpreted under 46 U.S.C. 14104(b), subject to any restrictions placed on the 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.

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.