46 CFR 10.109: Classification of merchant mariner endorsements
Last reviewed: October 14, 2026
This section classifies the endorsements on a merchant mariner credential (MMC) into four groups: national officer, national rating, tank vessel, and STCW. It names each endorsement in each group. It also points to the parts of this subchapter under which each group is established.
What it says
National officer endorsements are established in part 11 of this subchapter. They show that a holder of a valid MMC with the endorsement is qualified to serve in that capacity.
46 CFR 10.109(a)“The following national officer endorsements are established in part 11 of this subchapter.”
The national officer endorsements include Master, Chief Mate, Second Mate, Third Mate and Mate.
46 CFR 10.109(a)“(1) Master. (2) Chief Mate. (3) Second Mate. (4) Third Mate. (5) Mate.”
National rating endorsements are established in part 12 of this subchapter. They show that a holder of a valid MMC with the endorsement is qualified to serve in that capacity.
46 CFR 10.109(b)“The following national rating endorsements are established in part 12 of this subchapter.”
The Able Seafarer national rating endorsement comes in six types: Unlimited, Limited, Special, Offshore Supply Vessel (OSV), Sail, and Fishing Industry.
46 CFR 10.109(b)(1)“(1) Able Seafarer: (i) Unlimited; (ii) Limited; (iii) Special; (iv) Offshore Supply Vessel (OSV); (v) Sail; and (vi) Fishing Industry.”
Tank vessel endorsements are established in part 13 of this subchapter. They show that a holder of a valid MMC with the endorsement is qualified to serve in that capacity.
46 CFR 10.109(c)“The following ratings are established in part 13 of this subchapter.”
STCW endorsements are issued according to the STCW Convention, the STCW Code, and parts 11, 12, and 13 of this subchapter.
46 CFR 10.109(d)“The following STCW endorsements are issued according to the STCW Convention, the STCW Code, and parts 11, 12, and 13 of this subchapter.”
Common questions
Which part of the regulations establishes national officer endorsements?
Part 11 of this subchapter establishes the national officer endorsements. They are issued under the requirements in that part.
“The following national officer endorsements are established in part 11 of this subchapter.”
Which part establishes national rating endorsements such as Able Seafarer?
Part 12 of this subchapter establishes the national rating endorsements, which include Able Seafarer.
“The following national rating endorsements are established in part 12 of this subchapter.”
What are the tank vessel endorsements?
They are Tank Vessel-PIC, Tank Barge-PIC, Restricted Tank Vessel-PIC, Restricted Tank Barge-PIC, Tank Vessel-Assistant, and Tank Vessel-Engineer. Part 13 of this subchapter establishes them.
“The following ratings are established in part 13 of this subchapter.”
Where is the STCW Convention incorporated by reference?
The text sends the reader to § 10.103 for the incorporation by reference of the STCW Convention and STCW Code.
“as well as the STCW Convention and STCW Code (incorporated by reference, see § 10.103)”
The text of 46 CFR 10.109
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Classification of endorsements
(a) National officer endorsements. The following national officer endorsements are established in part 11 of this subchapter. The endorsements indicate that an individual holding a valid MMC with this endorsement is qualified to serve in that capacity and the endorsement has been issued under the requirements contained in part 11 of this subchapter:
(1) Master.
(2) Chief Mate.
(3) Second Mate.
(4) Third Mate.
(5) Mate.
(6) Master of Towing Vessels.
(7) Master of Towing Vessels-Limited.
(8) Mate (Pilot) of Towing Vessels.
(9) Apprentice Mate of Towing Vessels.
(10) Apprentice Mate of Towing Vessels-Limited.
(11) Assistance Towing.
(12) Offshore Installation Manager (OIM).
(13) Barge Supervisor (BS).
(14) Ballast Control Operator (BCO).
(15) Operator of Uninspected Passenger Vessels (OUPV).
(16) Master of Uninspected Fishing Industry Vessels.
(17) Mate of Uninspected Fishing Industry Vessels.
(18) Master-OSV.
(19) Chief Mate-OSV.
(20) Mate-OSV.
(21) Chief Engineer.
(22) Chief Engineer-Limited.
(23) First Assistant Engineer.
(24) Second Assistant Engineer.
(25) Third Assistant Engineer.
(26) Assistant Engineer-Limited.
(27) Designated Duty Engineer (DDE).
(28) Chief Engineer-OSV.
(29) Assistant Engineer-OSV.
(30) Chief Engineer-MODU.
(31) Assistant Engineer-MODU.
(32) Chief Engineer Uninspected Fishing Industry Vessels.
(33) Assistant Engineer Uninspected Fishing Industry Vessels.
(34) Radio Officer.
(35) First-Class Pilot.
(36) Chief Purser.
(37) Purser.
(38) Senior Assistant Purser.
(39) Junior Assistant Purser.
(40) Medical Doctor.
(41) Professional Nurse.
(42) Marine Physician Assistant.
(43) Medical Technician.
(44) High-Speed Craft Type Rating (HSC).
(45) Radar Observer.
(b) National rating endorsements. The following national rating endorsements are established in part 12 of this subchapter. The endorsements indicate that an individual holding a valid MMC with this endorsement is qualified to serve in that capacity and the endorsement has been issued under the requirements contained in part 12 of this subchapter:
(1) Able Seafarer:
(i) Unlimited;
(ii) Limited;
(iii) Special;
(iv) Offshore Supply Vessel (OSV);
(v) Sail; and
(vi) Fishing Industry.
(2) Ordinary Seafarer.
(3) Qualified Member of the Engine Department (QMED), including the following specialty endorsements:
(i) Oiler;
(ii) Boiler Technician;
(iii) Junior Engineer;
(iv) Pump Technician/Machinist; and
(v) Electrician/Refrigerating Engineer.
(4) Lifeboat Operator.
(5) Lifeboat Operator-Limited.
(6) Wiper.
(7) Steward's Department.
(8) Steward's Department Food Handler (F.H.).
(9) Cadet (Deck or Engine).
(10) Student Observer.
(11) Apprentice Engineer.
(12) Apprentice Mate.
(c) Tank Vessel Endorsements. The following ratings are established in part 13 of this subchapter. The national endorsements indicate that an individual holding a valid MMC with this endorsement is qualified to serve in that capacity and the endorsement has been issued under the requirements contained in part 13 of this subchapter:
(1) Tank Vessel-PIC.
(2) Tank Barge-PIC.
(3) Restricted Tank Vessel-PIC.
(4) Restricted Tank Barge-PIC.
(5) Tank Vessel-Assistant.
(6) Tank Vessel-Engineer.
(d) STCW endorsements. The following STCW endorsements are issued according to the STCW Convention, the STCW Code, and parts 11, 12, and 13 of this subchapter. The endorsements indicate that an individual holding a valid MMC with this endorsement is qualified to serve in that capacity and the endorsement has been issued under the requirements contained in parts 11, 12 or 13 of this subchapter as well as the STCW Convention and STCW Code (incorporated by reference, see § 10.103):
(1) Master.
(2) Chief Mate.
(3) Officer in Charge of a Navigational Watch (OICNW).
(4) Chief Engineer Officer.
(5) Second Engineer Officer.
(6) Officer In Charge of an Engineering Watch in a manned engineroom or Designated Duty Engineer in a periodically unmanned engineroom (OICEW).
(7) Electro-technical Officer (ETO).
(8) Rating Forming Part of a Navigational Watch (RFPNW).
(9) Able Seafarer-Deck.
(10) Rating Forming Part of an Engineering Watch in a manned engineroom or designated to perform duties in a periodically unmanned engineroom (RFPEW).
(11) Able Seafarer-Engine.
(12) Electro-technical Rating (ETR).
(13) Basic Training (BT).
(14) Advanced Firefighting.
(15) Proficiency in Survival Craft and Rescue Boats other than Fast Rescue Boats (PSC).
(16) Proficiency in Survival Craft and Rescue Boats other than Fast Rescue Boats-Limited (PSC-Limited).
(17) Proficiency in Fast Rescue Boats.
(18) Person in Charge of Medical Care.
(19) Medical First-aid Provider.
(20) GMDSS At-sea Maintainer.
(21) GMDSS Operator.
(22) Advanced Oil Tanker Cargo Operation.
(23) Advanced Chemical Tanker Cargo Operation.
(24) Advanced Liquefied Gas Tanker Cargo Operation.
(25) Basic Oil and Chemical Tanker Cargo Operation.
(26) Basic Liquefied Gas Tanker Cargo Operation.
(27) Vessel Security Officer (VSO).
(28) Vessel Personnel with Designated Security Duties.
(29) Security Awareness.
(30) High-Speed Craft Type Rating (HSC).
Sections it refers to
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.