"They thought it was a giant beach ball, they were going to bring in," said Marie Segneri, whose family found the orb floating near their rented beach house at Isle of Palms. "They swam out and said it was a very heavy ball, it was metal, had numbers on it, and there was no way they were bringing it in."
The ball eventually washed up on the shore, causing alarmed residents to call the police.
Authorities marked off an area around the orb with crime-scene tape and tried to identify it. They turned to members of the Air Force bomb squad, the Coast Guard and state officials for help, but no one could identify the strange object.
There were numbers on the surface of the orb, but no other clues that helped determine its origin.
NASA and the National Oceanic and Atmospheric Administration were contacted, but even they had no answers.
A Flotation Device... Maybe
Because of its weight — several hundred pounds — there's speculation it might be a flotation device used by a dredge company. But that theory only adds to the mystery — the orb has no fasteners on it where a line or cable might have been attached.
"We're calling it a UFO — an unidentified floating object," Isle of Palms Fire Chief Ann Graham told The Associated Press.
According to The Associated Press, the orb cracked in half as it was being brought to the town's public works department.
But the inside was as revealing as the outside — only seawater spilled out.
"There was nothing green, nothing glowing," Graham told the news agency. "It will probably just go to the scrap yard." 
ABCNEWS affiliate WCIV in Charleston, S.C., contributed to this report. | 
