vessel vs boat

vessel and boat both are nouns.

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

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

vessel (noun)	boat (noun)
a craft designed for water transportation	a small vessel for travel on water
an object used as a container (especially for liquids)	a dish (often boat-shaped) for serving gravy or sauce
a tube in which a body fluid circulates

vessel (verb)	boat (verb)
	ride in a boat on water