I replaced the original Fresnel formula with Schlick's Approximation.
Had to increase brightness of sky, as the water reflected less.
Had to increase the normal bending of the waves for them to be noticeable.
With those changes, the water looked more natural.
Found a couple of optical mistakes:
Fresnel was being modified by shadows.
Specularity was being modified by shadows.
One final unresolved problem is the reflections of terrain and objects are much fainter than they used to be.
Another feature I wanted to implement was blurring of refracted ocean bottom by means of LOD biasing the texture read, but it seemed to have no effect.