vessel vs fishing smack

vessel and fishing smack both are nouns.

Word	Noun	Adjective	Verb	Adverb
vessel	Yes	No	No	No
fishing smack	Yes	No	No	No

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

vessel: a craft designed for water transportation
fishing smack: a vessel for fishing; often has a well to keep the catch alive

vessel (noun)	fishing smack (noun)
a craft designed for water transportation	a vessel for fishing; often has a well to keep the catch alive
an object used as a container (especially for liquids)
a tube in which a body fluid circulates