Not quite sure what you guys are on about above but..
If it's the water that looks odd and you need it sorted~
Just change the ocean height number to something HIGHER, this will make it go further up.
If it's the texture that needs sorting~
Just click on the little arrow pointing to the right under "Terrain Texture" and change the 2nd, and 3rd texture as well, when you start plain off just adding a terrainmask to your map, two of the textures start of with plain black textures, you must set these yourself to whatever you prefer.
It's a bit unnecessary to start diddling with the heightmap before you actually used to map tools and see if they sort your issues. Just extra work otherwise.