submerse vs go under

submerse and go under both are verbs.

Word	Noun	Adjective	Verb	Adverb
submerse	No	No	Yes	No
go under	No	No	Yes	No

As verbs, go under is a hypernym of submerse; that is, go under is a word with a broader meaning than submerse:

Other hypernyms of submerse include go down, settle, sink.

submerse (verb)	go under (verb)
put under water	be called; go by a certain name
sink below the surface; go under or as if under water	go under
	disappear beyond the horizon