pond-skater vs water skater

pond-skater and water skater both are nouns.

Word	Noun	Adjective	Verb	Adverb
pond-skater	Yes	No	No	No
water skater	Yes	No	No	No

As nouns, pond-skater and water skater are synonyms defined as:

pond-skater and water skater: long-legged bug that skims about on the surface of water

Other synonyms of pond-skater include water strider.

pond-skater (noun)	water skater (noun)
long-legged bug that skims about on the surface of water	long-legged bug that skims about on the surface of water