fishing vessel vs watercraft

fishing vessel and watercraft both are nouns.

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

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

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

Other hypernyms of fishing vessel include vessel.

fishing vessel (noun)	watercraft (noun)
a vessel for fishing; often has a well to keep the catch alive	a craft designed for water transportation
	skill in the management of boats