pleasure boat vs motorboat

pleasure boat and motorboat both are nouns.

Word	Noun	Adjective	Verb	Adverb
pleasure boat	Yes	No	No	No
motorboat	Yes	No	Yes	No

As nouns, motorboat is a hypernym of pleasure boat; that is, motorboat is a word with a broader meaning than pleasure boat:

pleasure boat: a large motorboat that has a cabin and plumbing and other conveniences necessary for living on board
motorboat: a boat propelled by an internal-combustion engine

Other hypernyms of pleasure boat include powerboat.

pleasure boat (noun)	motorboat (noun)
a large motorboat that has a cabin and plumbing and other conveniences necessary for living on board	a boat propelled by an internal-combustion engine

pleasure boat (verb)	motorboat (verb)
	ride in a motorboat