If there is no "textures/atlantis/ocean" physical texture, then you obviously cannot enter that as an editorimage. Otherwise the shader you started with looks just fine. If it doesn't work, it's either because you haven't entered your shader file's name in the shaderlist or your Radiant and/or game installation is screwed.
Might be the latter case, because you certainly are having far more problems with basic shaders than anybody I have seen before.
Frozen by ICARUS