Yes, a skydome will help, possibly improved with the texture fed to the Ambient Color input rather than the default Diffuse Color. Also, Reflection nodes, using the Spherical Reflection method. Both of these overlap with the Poser 6 IBL options. And you probably need raytracing and Refraction. What makes the difference, however achieved, is the water being rendered with light coming from all directions. And another useful trick is to add textures to the ordinary lights. I've an RDNA freebie that does that, with tree-branch patterns. It does make a difference to woodland scenes.