46 CFR 15.404: Credentials required to serve onboard vessels
Last reviewed: October 14, 2026
This section sets the credentials a person must hold to serve in certain ratings and roles onboard a vessel. It covers watch ratings, Able Seafarer, QMED, lifeboat and fast rescue boat duties, entry-level ratings, medical care, and GMDSS radio duties. Many roles on vessels subject to the STCW Convention also need an STCW endorsement.
Applies toPersons serving in the listed ratings and roles on U.S.-flagged vessels or on vessels subject to the STCW Convention, as each paragraph states.
What it says
Each person serving as an RFPNW on a seagoing vessel of 500 GT or more, subject to the STCW Convention, must hold an STCW endorsement attesting to their qualifications to perform the navigational function at the support level.
46 CFR 15.404(a)“Each person serving as an RFPNW on a seagoing vessel of 500 GT or more, subject to the STCW Convention”
Each person serving as a rating as Able Seafarer on a U.S.-flagged vessel must hold an MMC endorsed as Able Seafarer.
46 CFR 15.404(b)“Each person serving as a rating as Able Seafarer on a U.S.-flagged vessel must hold an MMC endorsed as Able Seafarer”
No Able Seafarer credential is required of any person employed on any tug or towboat on the bays and sounds connected directly with the seas, or on any barges except seagoing barges or tank barges.
46 CFR 15.404(b)“no credential as Able Seafarer is required of any person employed on any tug or towboat on the bays and sounds connected directly with the seas, or on any barges except seagoing barges or tank barges”
A QMED may serve as a qualified rating in the engine department only in the specific ratings endorsed on their MMC.
46 CFR 15.404(d)(2)“A QMED may serve as a qualified rating in the engine department only in the specific ratings endorsed on their MMC.”
Every person assigned duties as a Lifeboat Operator must hold a credential attesting to such proficiency.
46 CFR 15.404(e)“Every person assigned duties as a Lifeboat Operator must hold a credential attesting to such proficiency.”
Every person employed in a rating other than Able Seafarer or QMED on a U.S. flagged vessel on which MMCs are required must hold an MMC endorsed as Wiper, Ordinary Seafarer, Steward's Department, or Steward's Department Food Handler (F.H.).
46 CFR 15.404(h)“Every person employed in a rating other than Able Seafarer or QMED on a U.S. flagged vessel on which MMCs are required must hold an MMC endorsed as Wiper, Ordinary Seafarer, Steward's Department, or Steward's Department Food Handler (F.H.).”
Every person designated to provide medical first aid onboard vessels subject to the STCW Convention must hold an MMC endorsed as Medical First-aid Provider or a deck or engineer officer endorsement.
46 CFR 15.404(j)“must hold an MMC endorsed as Medical First-aid Provider or a deck or engineer officer endorsement”
Every person responsible for the operation or shipboard maintenance of GMDSS radio equipment onboard vessels subject to the STCW Convention must hold an MMC endorsed as GMDSS Radio Operator or GMDSS Radio Maintainer, as appropriate.
46 CFR 15.404(k)“must hold an MMC endorsed as GMDSS Radio Operator or GMDSS Radio Maintainer, as appropriate.”
Common questions
Do I need an Able Seafarer credential on a tug or towboat?
Not on a tug or towboat on the bays and sounds connected directly with the seas. The text gives no such exception for tugs or towboats elsewhere.
“no credential as Able Seafarer is required of any person employed on any tug or towboat on the bays and sounds connected directly with the seas”
Can a QMED serve in any engine department rating?
A QMED may serve in any unqualified engine department rating without another endorsement. A QMED may serve in a qualified rating only in the specific ratings endorsed on their MMC.
“may serve in any unqualified rating in the engine department without obtaining an additional endorsement”
What is required to provide medical first aid on an STCW vessel?
The person must hold an MMC endorsed as Medical First-aid Provider or a deck or engineer officer endorsement.
“Every person designated to provide medical first aid onboard vessels subject to the STCW Convention”
The text of 46 CFR 15.404
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Requirements for serving onboard a vessel
(a) Ratings Forming Part of a Navigational Watch (RFPNW). Each person serving as an RFPNW on a seagoing vessel of 500 GT or more, subject to the STCW Convention (incorporated by reference, see § 15.103), must hold an STCW endorsement attesting to their qualifications to perform the navigational function at the support level.
(b) Able Seafarer. Each person serving as a rating as Able Seafarer on a U.S.-flagged vessel must hold an MMC endorsed as Able Seafarer, except that no credential as Able Seafarer is required of any person employed on any tug or towboat on the bays and sounds connected directly with the seas, or on any barges except seagoing barges or tank barges. Each person serving as an Able Seafarer on a seagoing vessel subject to the STCW Convention must also hold an STCW endorsement as Able Seafarer-Deck.
(c) Ratings Forming Part of an Engineering Watch (RFPEW). Each person serving as an RFPEW in a manned engineroom or designated to perform duties in a periodically unmanned engineroom, on a seagoing vessel driven by main propulsion machinery of 1,000 HP/750 kW propulsion power or more, must hold an STCW endorsement attesting to their qualifications to perform the marine-engineering function at the support level.
(d) Qualified Member of the Engine Department (QMED). (1) The holder of an MMC endorsed with one or more QMED ratings may serve in any unqualified rating in the engine department without obtaining an additional endorsement.
(2) A QMED may serve as a qualified rating in the engine department only in the specific ratings endorsed on their MMC.
(3) Persons serving on vessels subject to the STCW Convention as Junior Engineer, Pump Technician/Machinist, or Electrician/Refrigeration Engineer must also hold an STCW endorsement as Able Seafarer-Engine.
(e) Lifeboat Operator. Every person assigned duties as a Lifeboat Operator must hold a credential attesting to such proficiency. Persons serving on vessels subject to the STCW Convention must also hold an STCW endorsement in Proficiency in Survival Craft and Rescue Boats other than Fast Rescue Boats (PSC).
(f) Lifeboat Operator-Limited. Every person assigned duties onboard a vessel that is not required to carry lifeboats and is required to employ a Lifeboat Operator must hold an endorsement as either Lifeboat Operator or Lifeboat Operator-Limited. Persons serving on vessels subject to the STCW Convention must also hold an STCW endorsement in Proficiency in Survival Craft and Rescue Boats other than Lifeboats and Fast Rescue Boats-Limited (PSC-Limited).
(g) Fast Rescue Boats. Every person engaged or employed in a position requiring Proficiency in Fast Rescue Boats must hold an endorsement attesting to such proficiency.
(h) Entry level. Every person employed in a rating other than Able Seafarer or QMED on a U.S. flagged vessel on which MMCs are required must hold an MMC endorsed as Wiper, Ordinary Seafarer, Steward's Department, or Steward's Department Food Handler (F.H.).
(i) Person in Charge of Medical Care. Every person designated to take charge of medical care onboard vessels subject to the STCW Convention must hold an MMC endorsed as Person in Charge of Medical Care.
(j) Medical First-aid Provider. Every person designated to provide medical first aid onboard vessels subject to the STCW Convention must hold an MMC endorsed as Medical First-aid Provider or a deck or engineer officer endorsement.
(k) GMDSS Radio Operator or Maintainer. Every person responsible for the operation or shipboard maintenance of GMDSS radio equipment onboard vessels subject to the STCW Convention must hold an MMC endorsed as GMDSS Radio Operator or GMDSS Radio Maintainer, as appropriate.
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.