Not a lot ducks this season. Have not seen a Bluebill or a Merganser or anything except a Ruddy and Bufflehead. I love to watch them dive and puddle about. A Ruddy duck has a distinctive sharp tail when resting. When it dives that tail spreads wide to help it push down into the water.
Here's a couple shots from today that show a Ruddy atop the water and one into a dive.