Length 8 or 9 mm. A dark brown/black diving beetle usually with pale spots on the elytra. Similar (but usually smaller) spots occur in other species. The elytra are covered in a fine mesh-like reticulated micro-sculpture. A row of fine punctures runs alongside each side of the elytral suture.

Small water courses such as wet ditches and streams.

All year peaking April to October.

Widespread and fairly frequent in Britain.

Fairly frequent in Leicestershire and Rutland.