This is one of the refreshing, holiday scenes that typically inspire me (and make me nostalgic when I live far from the ocean). I first tried to process in Substance Alchemist some sand and pebble surface scans I did in Brittany a while ago, but lighting conditions on the field were not perfect and my scans were not good either, so I went for a material study in Substance Designer instead. This is what I came up with.
The material is 100% procedural, created in Substance Designer and rendered in Blender Eevee.
Some reference pictures from Beg an Dorchenn, Plomeur, France: