body of water vs offing

body of water and offing both are nouns.

Word	Noun	Adjective	Verb	Adverb
body of water	Yes	No	No	No
offing	Yes	No	No	No

As nouns, offing is a hyponym of body of water; that is, offing is a word with a more specific, narrower meaning than body of water:

body of water: the part of the earth's surface covered with water (such as a river or lake or ocean)
offing: the part of the sea that can be seen from the shore and is beyond the anchoring area

body of water (noun)	offing (noun)
the part of the earth's surface covered with water (such as a river or lake or ocean)	the part of the sea that can be seen from the shore and is beyond the anchoring area
	the near or foreseeable future