Ansys Employee

Interiors are boundaries between cell zones or the facets that make up the volume mesh and should be left alone. There are exceptions, but this isn't one of them. 

I assume you mean Ansys Meshing and not CFX? Did you set Fluent as the CFD solver at the mesh stage? 

Bottom is -5.6m? Double check the wave height definition, I can never remember if it's amplitude or displacement from mean.