Usage of "sea" vs "ocean" in names

Currently there is a mix of variable names using "ocean" and "sea", without a clear concept of what, if anything, is the difference between the two. Or if one word was chosen over the other for any reason other than etymology. "Sea" seems to be the more prevalent of the two.

We know not every sea is an ocean, but is every ocean a sea? If so, is standardizing on "sea" preferable, being the more general word?

For the name `skin_temperature_at_surface_over_ocean`, the people in my sphere would prefer to use "sea" instead of "ocean". Why was "ocean" chosen here?

Is there ever a use case for using "water", if the lake/sea/ocean distinction is unimportant? Currently there is both `lake_depth` and `sea_water_depth`. (And the description of `sea_water_depth` is "The depth of the ocean floor below the surface of the sea," which highlights the interchangeability of the two words.)

If we want to continue to use a mix of the two words, it would be nice to have a clearer description of why and when each should be used.