Yes they are Eastern Diamondbacks. The smaller one did not have any rattles only a bud.
I was hiking in central Florida and came across an Eastern Diamondback that was around 7 ft long. It coiled up and made a heck of a racket. I watched it from a safe distance. Even though I knew it could only strike 2-3 ft I kept about a 10 ft distance. It was really angry at me being there!