This is a small (2.5 mm), but sturdy bug and is almost a scale model of the Water Boatman, though its outline is higher and more compact. It is a good swimmer, and as the name indicates it swims on its back, with the silvery reflecting air bubble on the belly upward.

Occurs in a wide range of aquatic habitats including ponds, lakes and slow moving rivers.

All year round.

It hunts for Water Fleas and other small animals.

Widespread and fairly frequent in England and Wales.

Fairly frequent in Leicestershire and Rutland.