How to remove sea in the scene?

In an empty stage, with a terrain without textures and the sea, the graphics card is very forced, even with low settings.

Would it be possible to eliminate the sea in the scene?

Terrain->Edit Terrain

Modify->Remove Ocean

Glad you were able to resolve this, @kaito!

With low settings, and sea removed, I managed to remove the stress on the graphics card while using the editor.