For some reason textures only work with Nor in blender for me, and i am trying to create water with a Disp map, but when i hit render, the plane is mostly if not completely unnaffected by it, and i turned disp up all the way…I’m stumped, can anybody help me figure this one out? Any help is appreciated, as always. Thanks! 
Displacement mapping only works on existing vertices. So a plane (contains 4 vertices) will not show any real improvement.
Select your plane, Tab into Edit Mode, select all vertices, and subdivide four or five times (or more, if necessary…).
Hope this helps.
awesome! thanks!
I think the documentation says something about how it works best when the subsurface mesh is enabled. Try working a subsurf in, and that might help.