"Patches Of Sand Floating On Top Of Water Near Shoreline, Each Patch Around 4-10cm In Diameter"
"It's dry sand floating on the water tension, been picked up by the raising tide. Only happens when it's hot enough to dry the sand and absolutely flat calm."
Looking back at older posts, it's been this way for a while.
Now it's going to bug me.
#19 often seen in old cartoons like Tom and Jerry. :-)