surfboarding vs aquatics

surfboarding and aquatics both are nouns.

Word	Noun	Adjective	Verb	Adverb
surfboarding	Yes	No	No	No
aquatics	Yes	No	No	No

As nouns, aquatics is a hypernym of surfboarding; that is, aquatics is a word with a broader meaning than surfboarding:

surfboarding: the sport of riding a surfboard toward the shore on the crest of a wave
aquatics: sports that involve bodies of water

Other hypernyms of surfboarding include water sport.

surfboarding (noun)	aquatics (noun)
the sport of riding a surfboard toward the shore on the crest of a wave	sports that involve bodies of water