sea captain vs skipper

sea captain and skipper both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea captain	Yes	No	No	No
skipper	Yes	No	Yes	No

As nouns, sea captain and skipper are synonyms defined as:

sea captain and skipper: an officer who is licensed to command a merchant ship

Other synonyms of sea captain include captain, master.

sea captain (noun)	skipper (noun)
an officer who is licensed to command a merchant ship	the naval officer in command of a military ship
	an officer who is licensed to command a merchant ship
	a student who fails to attend classes

sea captain (verb)	skipper (verb)
	work as the skipper on a vessel