aquatics vs surfriding

aquatics and surfriding both are nouns.

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

As nouns, surfriding is a hyponym of aquatics; that is, surfriding is a word with a more specific, narrower meaning than aquatics:

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

Other hyponyms of aquatics include swim, swimming, surfboarding, surfing, water-skiing.

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