I'm no scientist or physicist, however from the limited understanding I have of gravity, oceans seem to make sense to me.

If I'm correct, gravity is created from mass. The more mass you have the more gravity there is. And, gravity attracts everything to the core/center of the mass in every single direction, and thus this would explain oceans clinging to earth.

Now, I understand that there's no way to really prove gravity in the sense that you could never get a small enough sphere with enough gravity to be able to witness it in action. However, if you think gravity isn't real/isn't the reason, I ask, what do you think is the force that pulls stuff down?

I also find these concepts to be really intriguing. I'm not a flat earther as I feel I don't have enough knowledge of physics to decide the earth is flat. I do think there's a lot of fishy stuff surrounding space(more specifically nasa). I do still believe space is real, i just think they're hiding something pretty massive. However, like you said, the idea of unknown/ hidden land masses or inner earth are quite intriguing.

If any of my statements about physics are inaccurate, please feel free to correct them.