In contrast to the usual belief that ducks can't fly, it is surprising that ducks can fly even to the extent of 60 mph. But usually they don't fly and this kind of speed can be achieved only when they are chasing their prey. This behaviour of ducks is not an unusual one and there are several other species also that perform well when need arises.

Usually we find that ducks don't fly and they just waddle around on their feet. They also swim in water and their webbed feet helps them in swimming. There is another distinction also that helps them in being in water. The feathers they have has a coat of a wax kind of substance and it helps them to overcome any kind of water if there is any that fall on them from above.

 In a quick burst of speed, up to 60 mph / 95 kmph. This would typically happen when said duck is trying to evade a predator (peregrine falcon or similar).

The eider duck has the distinction of being the fastest species (of all birds) reliably clocked on a long-distance flight, doing a steady 47 mph (75 kmph).

Most ducks are not fast flyers, though, and would be more likely to do something like a steady 20 mph / 32 kmph on a long-distance journey.

All of that is assuming travel in still air. With a tailwind, of course, ducks can hit much higher speeds. Or conversely, they can end up barely scraping along if they are fighting a stiff headwind. Ducks often change what altitude they fly at, trying to catch a tailwind or avoid the worst of a headwind.

The most common duck species in the world is the Mallard (the green-headed duck you see in every pond in the northern hemisphere). Their top speed is about 47 mph / 78 kmph, but their cruising speed is probably about half of that.