surfing vs water sport

surfing and water sport both are nouns.

Word	Noun	Adjective	Verb	Adverb
surfing	Yes	No	No	No
water sport	Yes	No	No	No

As nouns, water sport is a hypernym of surfing; that is, water sport is a word with a broader meaning than surfing:

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

Other hypernyms of surfing include aquatics.

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