crewman vs yachtsperson

crewman and yachtsperson both are nouns.

Word	Noun	Adjective	Verb	Adverb
crewman	Yes	No	No	No
yachtsperson	Yes	No	No	No

As nouns, yachtsperson is a hyponym of crewman; that is, yachtsperson is a word with a more specific, narrower meaning than crewman:

Other hyponyms of crewman include hand, lascar, gob, Jack-tar, Jack, mariner, old salt, sea dog, seafarer, seaman, tar, water dog, water rat.

crewman (noun)	yachtsperson (noun)
a member of a work crew	a person who owns or sails a yacht
a member of a flight crew
any member of a ship's crew