(a) Persons enrolled in an engineer training program approved by the Coast Guard, and who present a letter or other documentary evidence that they are enrolled, may be issued an MMC endorsed as apprentice engineer and may be signed on ships as such. The endorsement as apprentice engineer may be in addition to other endorsements; however, this endorsement does not authorize the holder to replace any of the regular required crew.

(b) Persons holding the endorsement as apprentice engineer are deemed to be seamen.