This command initiates a dialog that allows the user to change 4 parameters that affect the wave texture model. 

The entire wave texture model is pretty much a hack that I came up with after many attempts to do something  to make the water look better than just a solid color.  The affect is achieved by varying the saturation level of the Water Color.  Just accept on faith that you can get some interesting effects with these parameters.

In my opinion, the texture improves the water appearance at any sub-division level, but is most pleasing at sub-divisions of 8 and higher.

The first of the 4 parameters, Wave Amplitude, is pretty self-explanatory.  It determines how subtle (or obnoxious) the wave texture will be.  Setting this parameter to zero will turn off the wave effect entirely.

The X Period and Z Period are used in a function to cause a “beat” effect.  Try varying these to make the distance between the “waves” larger and smaller.

Variegation is a parameter that controls some randomness at each polygon.  This allows for occasional “whitecaps”.