When birdwatching at freshwater sites, you are likely to see a group of common ducks that actively dive for food alongside the familiar dabbling ducks. 

While dabbling ducks mainly occur on still water, channels and slow-flowing rivers, diving ducks can also be found on moving freshwater or even at sea. 

This identification video will help you determine which diving duck species you are watching: Pochard, Scaup or Tufted Duck.