The Coast Guard can't confirm that a great white shark was seen at the Jersey Shore, just that a single boater radioed in a report.
"It was just a hey-let-me-tell-what-I-saw kind of thing," said Petty Officer Crystal Kneen, a Coast Guard spokeswoman based at Atlantic City.
The unknown caller said he saw a 12-footer on Sunday morning "at least 200 yards from the beach," off Island Beach State Park, south of Seaside Heights.
"Not too far from the nearest civilian bathing beach," said the man, who was in a boat named the Albacore.
The Coast Guard alerted local officials, Kneen said.
But no beaches were closed, according to reports.
Shark attacks are rare in New Jersey, and nowhere near as big a threat to swimmers as drowning. The last fatal attack was in 1926, according to the Florida Museum of National History's International Shark Attack File.
Four 1916 deaths attributed to a great white at the Shore may have inspired the book and movie Jaws.
In 2005, a teen surfer was bitten, possibly by a young great white, in early June off the 18th Street Beach in Surf City.
That was reportedly the first attack since late July 1980, when a Hatboro teen was bitten in Ocean City, possibly by a sandbar shark.