What's this Mystery Bird?

Help!

I live in Ohio and lately, my 8-year-old has been getting super interested in water birds. Well, we found this one bird the other day, and it has got us really stumped. We are having a super hard time trying to identify it! We've gone to whatbird.com, and it looks like it is either a Grebe or a Merganser, but the color pattern doesn't look quite right. I took a few blurry pictures. The bird won't let us get much closer without flying away. Here are a few things I noticed about it:

1. It's a diving bird. It goes under for 30 seconds or so, then comes back up, usually with something in its mouth!

2. It looks to be a little bigger than a mallard. Maybe the body is about the same size, but it is kind of hard to tell.

3. The neck is longer than a duck, like a goose.

4. It has a long yellowish or orangish beak/bill, which it likes to stick up in the air at an angle while it watches you.

5. Body color for two of them were completely brown/blackish. One of them had a lighter cream/white color running down its neck. (We saw 3 of them together.)

6. Had black legs. Maybe webbed feet, hard to tell.

7. When it swam, its body was more down in the water, rather than on top of it like a duck.

8. It didn't make any sounds.

9. When it landed after flying, it was really clumsy. Almost looked like it crashed on the ground.

Can anybody help me find out what that bird is? It would be awesome if we could figure it out!

Here are the pics: