narrowboat vs canal boat

narrowboat and canal boat both are nouns.

Word	Noun	Adjective	Verb	Adverb
narrowboat	Yes	No	No	No
canal boat	Yes	No	No	No

As nouns, narrowboat and canal boat are synonyms defined as:

narrowboat and canal boat: a long boat that carries freight and is narrow enough to be used in canals

Other synonyms of narrowboat include narrow boat.

narrowboat (noun)	canal boat (noun)
a long boat that carries freight and is narrow enough to be used in canals	a long boat that carries freight and is narrow enough to be used in canals