We encountered this goosander family when we were out walking in the Derwent Valley Country Park near Gateshead this afternoon. They were swimming under the Butterfly bridge on the river Derwent at Winlaton Mill just as were were walking over it.
This provided an unusual opportunity to watch them diving and chasing fish under water. By flicking that broad, fan-shaped tail downwards and kicking with those big feet they can dive in an instant and have an impressive turn of speed under water, chasing fish relentlessly.
There are three underwater in the picture above, and several more emerging under the other side of the bridge in the picture below.
In winter goosander are wary birds, difficult to approach, but in summer family parties like this are much more accommodating and rarely fly unless severely threatened.