The problem is you don't get transparency, which is the main goal of water
The water will be solid blue until the very shore edge, and then create hard pixel collisions against the shore. From space this isn't a issue, however, it is a issue that there is absolutely no shore transparency. Your terrain looks fake, and has no volume, just peaks out of the water.
What I mean by a solid shader is it will create displacement to whatever the height is set to, and it's volume completely transparent to said parent terrain. This allows you to use the water shader on a global scale, with volumetric effects. Currently we have a object. And terragen doesn't support object transparency with the water shader as it's surface, as then the parent surface becomes black, so the water is as blue as it can get, and has no transparency as it's just a surface effect with reflection.
This
"Solid" Surface Shader would act like a "Surface Shader" with a child set of nodes to be it's surface in whatever unique manner you see fit, but it's input would be the "Floor" of the surface, and it's volume (displacement) perfectly smooth wrapped around the sphere. Creating whatever depth surface you need.
This type of shader could be used for so much more then just water too.