Coopers Hawk

I believe this is a Coopers Hawk, but I always get confused, between this and a Sharp-Shinned.

 

I was a bit surprised to see this bird pretty close, and not get scared off. I moved in a little closer and got some shots. Then soon after it suddenly took off, and dove at the water. I am not sure what it got exactly (I think maybe a bufflehead!..), but it basically drowned another bird, and sat in the water for maybe 5 min. Then it suddenly took off, with the carcus into the bushes.

Done