marine vs subocean

marine is a noun but subocean is not a noun.

Word	Noun	Adjective	Verb	Adverb
marine	Yes	Yes	No	No
subocean	No	Yes	No	No

marine (noun)	subocean (noun)
a soldier who serves both on shipboard and on land

marine (adjective)	subocean (adjective)
relating to or characteristic of or occurring on or in the sea	formed or situated or occurring beneath the ocean or the ocean bed
of or relating to the sea
of or relating to military personnel who serve both on land and at sea (specifically the U.S. Marine Corps)
relating to or involving ships or shipping or navigation or seamen
native to or inhabiting the sea