Hydrophone placed about 6 inches below the sand at the shore line. The rustling is the sand moving across the microphone and you can also hear the rumble of the wind above ground.
This short clip was recorded at Winterton-on-Sea in Norfolk with a microphone pointing at the sea and a hydrophone just under the sand at the sea’s edge. You can hear the sea dragging the sand and shale over it.
It was pretty much the first time out with the hydrophone and I learned a lot.