I've been trying to wrap my head around these two. So, here are the two relevant examples of usage (from Cambridge Dictionary and a YT video):
When we use
under, we mean that one thing is touching or covering something else:
The wreck of the Titanic still remains under the sea.
beneath when we talk about things which are at a lower level than something else:
She hid beneath the water. (= the surface of the water)
beneath is less common in everyday speech.
So, is there a difference in meaning between 'beneath the sea' and 'under the sea' itself? If that depends entirely on the context, then, could you give some examples?