Sand is tricky.
How close do you need to get to it?
Even the smallest bit of granular roughness is too much - it is exagerrated.
But you can't consider the surface without the contour. The attached image shows sand applied to the water object - the closest thing to a programmed rippled surface. Pretty bad, depending on your distance....
In you neckoftheocean, perhaps the beaches are broad and have graceful dunes - these elements need to be modeled with the same attention as bedsheets would..
Sand has that sparkly twinkle - could do it with a specular mask, but in general, sand could use a high degree of specular reflection since it glares so much at low sun angles....
Dwight Atkinson