Drawing inspiration from Miller's planet in Interstellar, a vast water world with an endless ocean, and the design of the CASE robot, Tatehama, also known as CGBeginner, a self-taught CG Artist fascinated by Christopher Nolan's works, has created a similar simulation using Blender and the FLIP Fluids add-on.
The actual domain size is not that big, as you can see in the video's viewport render. CGBeginner applied an ocean displacement map to a small simulation object and applied the exact same displacement map to a large plane to make it look like a large-scale ocean simulation. The boundary between the fluid simulation object and the large plane object must be seamless. Following this post, CGBeginner used a Lattice modifier to set the displacement of the edges of the simulation object to zero.