Hey JerB;
In response to your inquiry; a fellow modeler friend of mine did a small vignette of the Normandy beach area. For his groundwork/sand he used Epoxy wood filler. According to him it gives you time to sculpt or move the epoxy around to your desired look but once it dries, it dries hard to sand or shape. This is how it initially looked. Good luck.
For some reason I can't see the pic