I didn't have enough flocking material to make a whole fourth board. I kept the fourth board with the sloping terrain that I built earlier, so I can flock it at a later date. I found a spare piece of foamboard sheeting, and cut it into a 'coastline' with a colour printed water layer on photo-paper beneath it, to make beach and coast! I had just enough flocking material to finish it :)
when applying devlan mud onto the flocking grit, I did it only softly brushing toward the coast, and left a good portion raw and un-washed, to make a beach area. I then brushed most of the 'sand' area with a pinky colour, and finished with the usual codex grey brush over the textured surface of the washed areas.