The breeze blew, and the water waves rose and fell one after another, creating circles of ripples and hitting the man on the shore.
There is gravel all around, especially the stones washed by water that are smooth and round.
But there are also sharp gravels that make people uncomfortable. The man was lying on the rounded stones with his face, and his right hand happened to hold a sharp stone. Maybe it was because the stones were uncomfortable, so the index finger of the man's right hand moved.
Intention: I will save you.