centerboard vs fin keel

centerboard and fin keel both are nouns.

Word	Noun	Adjective	Verb	Adverb
centerboard	Yes	No	No	No
fin keel	Yes	No	No	No

As nouns, fin keel is a hypernym of centerboard; that is, fin keel is a word with a broader meaning than centerboard:

centerboard: a retractable fin keel used on sailboats to prevent drifting to leeward
fin keel: a metal plate projecting from the keel of a shallow vessel to give it greater lateral stability

centerboard (noun)	fin keel (noun)
a retractable fin keel used on sailboats to prevent drifting to leeward	a metal plate projecting from the keel of a shallow vessel to give it greater lateral stability