I recently got to spend a couple of weeks at a cottage on Lake Muskoka in Ontario. The cottage is at the end of a bay and is very well protected from wind and boat traffic. There were a pair of ducks that I saw almost every day (as well as a beautiful Loon) and was able to get quite a bit of video of. I put some clips together (above) for you. I think these are Black Ducks because of the male/female similarity and the coloration, but I know very little about birds so I might be wrong about that. One website I saw suggested that Black Ducks would have a darker body. I would love correction if anyone knows that these are a different species.
What I loved most about getting to watch this pair so close up for so long was how they moved in sync. I don't think I really capture this in the video, but when they were in the water they were synchronized swimmers elegantly moving as one. Another think that struck me was how the duck's webbed foot spread out and contracted again gracefully underwater to minimize drag and maximize power from each stroke. It is hard to see in the low-quality video posted here, but it was something worthy of a dance performance.
The ducks seemed to tolerate our presence as well. I was able to walk up to within 5 feet of them without startling them (if I walked slowly). Any closer than that and they would simply turn and walk towards the water. Normally I am NOT in favor of interacting with wildlife in any way, but wildlife doesn't normally hang out just feet from me!