yacht vs vessel

yacht and vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
yacht	Yes	No	Yes	No
vessel	Yes	No	No	No

As nouns, vessel is a hypernym of yacht; that is, vessel is a word with a broader meaning than yacht:

yacht: an expensive vessel propelled by sail or power and used for cruising or racing
vessel: a craft designed for water transportation

Other hypernyms of yacht include watercraft.

yacht (noun)	vessel (noun)
an expensive vessel propelled by sail or power and used for cruising or racing	a craft designed for water transportation
	an object used as a container (especially for liquids)
	a tube in which a body fluid circulates

yacht (verb)	vessel (verb)
travel in a yacht