daggerboard vs sliding keel

daggerboard and sliding keel both are nouns.

Word	Noun	Adjective	Verb	Adverb
daggerboard	Yes	No	No	No
sliding keel	Yes	No	No	No

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

daggerboard: a removable centerboard on a small sailboat that can be lowered into the water to serve as a keel
sliding keel: a retractable fin keel used on sailboats to prevent drifting to leeward

Other hypernyms of daggerboard include centerboard, centreboard, drop keel.

daggerboard (noun)	sliding keel (noun)
a removable centerboard on a small sailboat that can be lowered into the water to serve as a keel	a retractable fin keel used on sailboats to prevent drifting to leeward