sailor boy vs bluejacket

sailor boy and bluejacket both are nouns.

Word	Noun	Adjective	Verb	Adverb
sailor boy	Yes	No	No	No
bluejacket	Yes	No	No	No

As nouns, sailor boy and bluejacket are synonyms defined as:

Other synonyms of sailor boy include navy man, sailor.

sailor boy (noun)	bluejacket (noun)
a serviceman in the navy	a serviceman in the navy