46 CFR 15.915: Engineer officer endorsements and authorized service
Last reviewed: October 14, 2026
This section lists the service that certain MMC engineer officer endorsements authorize. It covers the Designated Duty Engineer, Chief Engineer-Limited and Assistant Engineer-Limited endorsements. Service must stay within any restrictions on the MMC and as provided by § 15.401.
Applies toHolders of MMC officer endorsements for Designated Duty Engineer, Chief Engineer-Limited, and Assistant Engineer-Limited.
What it says
These endorsements authorize service only within any restrictions on the MMC and as provided by § 15.401.
“authorize the holder to serve as noted, within any restrictions on the MMC, and as provided by § 15.401”
A Designated Duty Engineer (DDE) endorsement authorizes service as Chief or Assistant Engineer on vessels of less than 500 GT.
46 CFR 15.915(a)“A Designated Duty Engineer (DDE) endorsement authorizes service as Chief or Assistant Engineer on vessels of less than 500 GT”
A DDE limited to vessels of less than 1,000 horsepower or less than 4,000 horsepower may serve only on near-coastal, Great Lakes, or inland waters.
46 CFR 15.915(a)(1)“may serve only on near-coastal, Great Lakes, or inland waters”
A DDE with no horsepower limitations may serve on any waters.
46 CFR 15.915(a)(2)“A DDE with no horsepower limitations may serve on any waters.”
When a DDE serves on a vessel to which STCW applies, the appropriate STCW endorsement must also be held.
46 CFR 15.915(a)(3)“When serving on a vessel to which STCW applies, the appropriate STCW endorsement must also be held.”
A Chief Engineer-Limited endorsement authorizes service as Chief or Assistant Engineer on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters.
46 CFR 15.915(b)“authorizes service as Chief or Assistant Engineer on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters”
An Assistant Engineer-Limited endorsement authorizes service on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters.
46 CFR 15.915(c)“An Assistant Engineer-Limited endorsement authorizes service on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters.”
Common questions
Where can a DDE with no horsepower limitations serve?
A DDE with no horsepower limitations may serve on any waters.
“A DDE with no horsepower limitations may serve on any waters.”
Does a DDE need an STCW endorsement?
Yes, when serving on a vessel to which STCW applies, the appropriate STCW endorsement must also be held.
“When serving on a vessel to which STCW applies, the appropriate STCW endorsement must also be held.”
What vessels can a Chief Engineer-Limited serve on?
A Chief Engineer-Limited may serve as Chief or Assistant Engineer on vessels of any gross tons on inland waters. On ocean, near-coastal, or Great Lakes waters, the vessel must be less than 1,600 GRT.
“authorizes service as Chief or Assistant Engineer on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters”
The text of 46 CFR 15.915
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Engineer officer endorsements
The following MMC officer endorsements authorize the holder to serve as noted, within any restrictions on the MMC, and as provided by § 15.401:
(a) A Designated Duty Engineer (DDE) endorsement authorizes service as Chief or Assistant Engineer on vessels of less than 500 GT in the following manners:
(1) A DDE limited to vessels of less than 1,000 horsepower or less than 4,000 horsepower may serve only on near-coastal, Great Lakes, or inland waters.
(2) A DDE with no horsepower limitations may serve on any waters.
(3) When serving on a vessel to which STCW applies, the appropriate STCW endorsement must also be held.
(b) A Chief Engineer-Limited endorsement authorizes service as Chief or Assistant Engineer on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters.
(c) An Assistant Engineer-Limited endorsement authorizes service on vessels of any gross tons on inland waters and of less than 1,600 GRT on ocean, near-coastal, or Great Lakes waters.
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.