Male & Female Banded Demoiselle (Calopteryx splendens)
I have a small number of favourite sites I return to year after year, in between exploring new one's in and around Sussex.
At one of these, one of my mid-summer joys is watching these delicate Damselflies darting over the water's surface, as if playing hop-scotch.
The Demoiselle can only truly be appreciated up close, so I did my best to do just that for this short video:

The banded demoiselle is a species of damselfly belonging to the family Calopterygidae. It is often found along slow-flowing streams and rivers. It is a Eurasian species occurring from the Atlantic coast eastwards to Lake Baikal and northwestern China. This is a common species throughout much of its range.