I was driving South on hwy 17 when I saw a black rectangular object cross over the road. My first thought was that a brid glided over the road. But then it occurred to me that it wasn't a bird, and a few seconds later as I got closer the the point where it crossed another one flew over the road, at which point it was closer. I wasn't sure what I saw. After I thought about it there were no visible engines, no wings, no horizontal stabilizers, no cockpit canopy, no rotor blades. Just a black rectangular shaped object of which I have never seen before. I cannot explain what I saw. It was flying as if it was follwing the creek or the marsh. When I got to the area they crossed I looked toward the East but I was unable to see them again. This was in broad daylight. The altitude was approximately 800-1000 ft. I still cannot believe what I saw.I was watching a ufo program which reminded me of the event. I wanted to put this on record so that maybe I could find out if some one had seen the same thing I saw. From where I was he objects would have been heading in the direction of Atkinson, Ga.