mid-water vs body of water

mid-water and body of water both are nouns.

Word	Noun	Adjective	Verb	Adverb
mid-water	Yes	No	No	No
body of water	Yes	No	No	No

As nouns, body of water is a hypernym of mid-water; that is, body of water is a word with a broader meaning than mid-water:

mid-water: the water that is well below the surface but also well above the bottom
body of water: the part of the earth's surface covered with water (such as a river or lake or ocean)

Other hypernyms of mid-water include water.

mid-water (noun)	body of water (noun)
the water that is well below the surface but also well above the bottom	the part of the earth's surface covered with water (such as a river or lake or ocean)