Submarine or Intramarine?

Doesn’t submarine mean UNDER the sea which means the ground or coral or muck at the bottom of the sea? If you agree with this, shouldn’t a more accurate term for submarine be intramarine?

Unless marine refers to the surface of an ocean or sea.

Well, mariners are people who travel across the surface, so ‘submarine’ could be anything below that level. Plus, there might be a conceptual thing where people looking at the ocean have no idea how deep it goes, and all the ocean is is what they can see. Anything below that level would be ‘submarine’.

E…rist: If we utilize your explanation, what term would you choose to refer to the rock, coral, or mud at the bottom of the sea or ocean? Sub-sub marine?