Fluid Effects > Ocean > Create Ocean >
Sets the options for creating an ocean. They are listed below.
Turn this option on to create a preview plane that shows a shaded patch of the ocean with displacement in shaded display mode. You can scale and translate it to preview different parts of the ocean. This plane is for preview only and will not render.
If you do not create this plane at the time you create the ocean, you can create the plane later by selecting the ocean plane and then selecting Fluid Effects > Ocean > Add Preview Plane.