The following licenses and MMC officer endorsements authorize the holder to serve as noted, within any restrictions on the license or MMC, and as provided by § 15.401 of this part:

(a) A designated duty engineer license or endorsement authorizes service as chief or assistant engineer on vessels of less than 500 GT in the following manners:

(1) A designated duty engineer 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 designated duty engineer 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) license or 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) license or 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.